Allow colon in socket path

[magnusvin]

Fixes a regression introduced by 3faf095 (GHSA-58cq-mgw2-38m5) that made host_port() reject server strings where the socket/port portion contains a colon, causing a spurious "Invalid server." error. This breaks connecting via socket paths that legitimately contain colons, e.g.:
:/cloudsql/project:region:instance (Google Cloud SQL Unix socket)
:/var/www/mysql.sock

Changes
adminer/include/auth.inc.php: allow : in the validated port/socket pattern ([-\w./]* → [-\w.:/]*), matching what host_port() can return.
adminer/include/functions.inc.php: host_port()'s port/socket capture group changed from [^:].+ to [^:].*. The .+ required at least 2 characters after the colon, so a single-character port (e.g. localhost:5) failed to match and was returned unsplit as the host instead of being split into (host, port). Since the host pattern permits colons, this let a single-character port slip past the privileged-port check (< 1024) entirely, as the port value it checks was left empty. .* restores splitting for 1-character ports/sockets too.

[vrana]

This would parse 2001:0db8:0:0:0:0:1428:57ab as host 2001 and port 0db8:0:0:0:0:1428:57ab.

[magnusvin]

Now is the change from ~^(\[(.+)]|([^:]*)):([^:]+)$~ to ~^(\[(.+)]|([^:]*)):(\d+|/.+)$~, short from ([^:]+) to (\d+|/.+).

Tested these values:

Server	Host	Port
localhost:/var/www/mysql.sock	localhost	/var/www/mysql.sock
localhost:3306	localhost	3306
[::1]:/var/www/mysql.sock	::1	/var/www/mysql.sock
[::1]:3306	::1	3306
db-master:3306	db-master	3306
:/var/www/mysql.sock		/var/www/mysql.sock
:/cloudsql/project:region:instance		/cloudsql/project:region:instance
[2001:0db8:0:0:0:0:1428:57ab]:/var/www/mysql.sock	2001:0db8:0:0:0:0:1428:57ab	/var/www/mysql.sock
[2001:0db8:0:0:0:0:1428:57ab]:/cloudsql/project:region:instance	2001:0db8:0:0:0:0:1428:57ab	/cloudsql/project:region:instance
[2001:0db8:0:0:0:0:1428:1428]:/cloudsql/project:region:instance	2001:0db8:0:0:0:0:1428:1428	/cloudsql/project:region:instance
[2001:0db8:0:0:0:0:1428:1428]:3306	2001:0db8:0:0:0:0:1428:1428	3306
[2001:0db8:0:0:0:0:1428:57ab]:3306	2001:0db8:0:0:0:0:1428:57ab	3306

[vrana]

Thank you, I will fix it together with other problems this caused.