ConnectionContext prompts for credentials with X.509 certificate authentication

[AdeshShambhu]

Component: hana-ml Python library

Issue: When using X.509 certificate authentication for Hana Cloud, ConnectionContext incorrectly prompts for username/password interactively, causing execution to hang.

Expected Behavior: ConnectionContext should accept X.509 authentication parameters (authenticationMethods='X509', authenticationX509=) and create a connection without prompting for credentials, similar to how hdbcli.dbapi.connect() works.

Actual Behavior: Even when X.509 parameters are provided, ConnectionContext.init() triggers getpass.getpass() prompting for password interactively. In non-interactive environments, this causes the application to hang indefinitely.
The check doesn't account for X.509 authentication (passed via **properties), so when password=None and no userkey is provided, it still prompts even though X.509 credentials are present.

Reproduction:

from hana_ml.dataframe import ConnectionContext
                                                                                                                                                                   
 conn = ConnectionContext(                                                                                                                                         
     address='<hana-host>',                                                                                                                                        
     port=443,                                                                                                                                                     
     encrypt=True,                                                                                                                                                 
     sslCryptoProvider='openssl',
     authenticationMethods='X509',                                                                                                                                 
     authenticationX509='<certificate-pem-string>',                                                                                                                    
     currentSchema='MY_SCHEMA'                                                                                                                                     
 ) 

==> Hangs waiting for user/namepassword input

Workaround:
Pass user='' and password='' (empty strings, not None) to bypass the prompt:

conn = ConnectionContext(                                                                                                                                         
      address='<hana-host>',                                                                                                                                        
      port=443,                                                                                                                                                     
      user='',  # Empty string prevents prompt
      password='',  # Empty string prevents prompt                                                                                                                  
      encrypt=True,                                                                                                                                                 
      sslCryptoProvider='openssl',                                                                                                                                  
      authenticationMethods='X509',                                                                                                                                 
      authenticationX509='<certificate-string>',                                                                                                                    
      currentSchema='MY_SCHEMA'                                                                                                                                     
  )  

Impact:

• Breaks X.509 authentication in non-interactive environments
• Affects Cloud Foundry deployments, Kubernetes jobs, CI/CD pipelines
• Forces users to use workarounds or avoid ConnectionContext entirely

[cmog]

@raymondyao could you check this?