Remove unneeded flush privilege command

The flush privilege command is only needed if the acl tables are edited
manually

Thanks to Daniel Black for the contriubtion

(cherry picked from commit df21f5c)

Author: ltangvald

template/docker-entrypoint.sh

@@ -135,7 +135,6 @@ EOF
 				echo "GRANT ALL ON \`"$MYSQL_DATABASE"\`.* TO '"$MYSQL_USER"'@'%' ;" | "${mysql[@]}"
 			fi
 
-			echo 'FLUSH PRIVILEGES ;' | "${mysql[@]}"
 		elif [ "$MYSQL_USER" -a ! "$MYSQL_PASSWORD" -o ! "$MYSQL_USER" -a "$MYSQL_PASSWORD" ]; then
 			echo '[Entrypoint] Not creating mysql user. MYSQL_USER and MYSQL_PASSWORD must be specified to create a mysql user.'
 		fi