Remove mumble directory

src/freedombone-app-mumble

         rm /etc/mumble-server.ini
     fi
     remove_certs mumble
+    if [ -d /var/lib/mumble-server ]; then
+        rm -rf /var/lib/mumble-server
+    fi
     function_check remove_onion_service
     remove_onion_service mumble ${MUMBLE_PORT}
     sed -i '/mumble/d' $COMPLETION_FILE