Fix stale hardcoded wifi-corp SSID in portal config dump (use $ESSID_MGT/$CHANNEL_MGT)

Author: r4ulcl

APs/config/html/index.php.tmp

@@ -204,8 +204,8 @@ private_key     = /root/certs/server.key
 private_key_passwd = whatever
 dh_file         = /etc/hostapd-wpe/dh
 
-ssid    = wifi-corp
-channel = 44</pre>";
+ssid    = $ESSID_MGT
+channel = $CHANNEL_MGT</pre>";
     echo "<p>Certificate Authority: <a href=\"/.internalCA/ca.crt\">http://{$_SERVER['SERVER_ADDR']}/.internalCA/ca.crt</a></p>";
 }