Replace oursql with PyMySQL

Since this is prefered on toolsforge and works out of the box after
installing via pip, replace oursql which caused some problems.
Especially oursql was not able to connect to db via ssh tunnel.

Related Task: [FS#144](https://fs.golderweb.de/index.php?do=details&task_id=144)

lib/mysqlred.py

@@ -46,12 +46,13 @@ import sqlalchemy.types as types
 
 Base = declarative_base()
 
-url = URL( "mysql+oursql",
+url = URL( "mysql+pymysql",
            username=config.db_username,
            password=config.db_password,
            host=config.db_hostname,
            port=config.db_port,
            database=config.db_username + jogobot.config['db_suffix'] )
+
 engine = create_engine(url, echo=True)