remove missed postgres

Author: nasc17

src/azure-cli/azure/cli/command_modules/rdbms/_params.py

@@ -215,7 +215,6 @@ def _complex_params(command_group):  # pylint: disable=too-many-statements
 
     _complex_params('mariadb')
     _complex_params('mysql')
-    _complex_params('postgres')
 
     # Flexible-server
     # pylint: disable=too-many-locals, too-many-branches