sql: only consider known valid connection parameters (#17143)

wcs/sql.py

@@ -240,9 +240,10 @@ def get_connection(new=False):
         cleanup_connection()
     if not hasattr(get_publisher(), 'pgconn') or get_publisher().pgconn is None:
         postgresql_cfg = {}
-        for k, v in get_cfg('postgresql', {}).items():
-            if v and isinstance(v, basestring):
-                postgresql_cfg[k] = v
+        for param in ('database', 'user', 'password', 'host', 'port'):
+            value = get_cfg('postgresql', {}).get(param)
+            if value:
+                postgresql_cfg[param] = value
         try:
             get_publisher().pgconn = psycopg2.connect(**postgresql_cfg)
         except psycopg2.Error: