fix typo

Author: ipontt

stubs/mysql.stub

@@ -9,7 +9,7 @@ mysql:
         MYSQL_USER: '${DB_USERNAME}'
         MYSQL_PASSWORD: '${DB_PASSWORD}'
         MYSQL_ALLOW_EMPTY_PASSWORD: 1
-        MYSQL_EXTRA_OPTIONS: '${MYSQL_EXTRA_OPTIONS}
+        MYSQL_EXTRA_OPTIONS: '${MYSQL_EXTRA_OPTIONS}'
     volumes:
         - 'sail-mysql:/var/lib/mysql'
         - './vendor/laravel/sail/database/mysql/create-testing-database.sh:/docker-entrypoint-initdb.d/10-create-testing-database.sh'