Task #10811: default postgres port is 5432

LCS/PyCommon/dbcredentials.py

@@ -82,7 +82,7 @@ class Credentials:
     """
     return {
       "host": self.host,
-      "port": self.port or -1,
+      "port": self.port if self.port >= 0 else 5432,
 
       "user": self.user,
       "passwd": self.password,