Build the db connection on `"postgres"` instead of `"template1"`

According to the postgresql docs[1], you should not have a connection with
`"template1"` when copying multiple databases.

[1]: http://www.postgresql.org/docs/9.1/static/manage-ag-templatedbs.html

lib/ansible/modules/database/postgresql/postgresql_db.py

@@ -275,7 +275,7 @@ def main():
         kw["host"] = module.params["login_unix_socket"]
 
     try:
-        db_connection = psycopg2.connect(database="template1", **kw)
+        db_connection = psycopg2.connect(database="postgres", **kw)
         # Enable autocommit so we can create databases
         if psycopg2.__version__ >= '2.4.2':
             db_connection.autocommit = True