v1.16.4

Changelog

• a689ce3 Merge pull request #215 from V01d42/add-generate-url
• d8163a4 add docs description about MYSQL_USER, MYSQL_PASSWORD, MYSQL_HOST, MYSQL_PORT, MYSQL_DATABASE
• 80cabb5 add logs when load mysql_url from other env value
• a0b9413 generate mysqlURL from host, port, user, password, database