Explicitly set charset for PyMySQL-Connection

Since PyMySQL-Connection otherwise uses charset 'latin-1', explicitly
set connection charset to 'utf8'

http://docs.sqlalchemy.org/en/rel_1_0/dialects/mysql.html#charset-selection
http://docs.sqlalchemy.org/en/rel_1_0/core/engines.html?highlight=url#sqlalchemy.engine.url.URL

Related Task: [FS#156](https://fs.golderweb.de/index.php?do=details&task_id=156)

lib/mysqlred.py

@@ -51,7 +51,8 @@ url = URL( "mysql+pymysql",
            password=config.db_password,
            host=config.db_hostname,
            port=config.db_port,
-           database=config.db_username + jogobot.config['db_suffix'] )
+           database=config.db_username + jogobot.config['db_suffix'],
+           query={'charset': 'utf8'} )
 
 engine = create_engine(url, echo=True)