fixed travis mysql-server install
fixed travis mysql-server install

Signed-off-by: André Bauer <0045e911dda405b74e498edd0b59617cdc330077@gmail.com>

zammad/zammad,monotek/zammad,zammad/zammad,zammad/zammad,monotek/zammad,monotek/zammad,monotek/zammad,zammad/zammad,monotek/zammad,zammad/zammad,zammad/zammad,monotek/zammad