When editing the Database URL, a driver error appears

Steps to reproduce:

1) Install a Confluence - tested on version 5.2.3
2) On Database URL, remove the string "jdbc:mysql://"
3) As expected the connection will not happen, however the error suggests a driver issue, instead of accusing the URL to be wrong:

The following error(s) occurred:

• Configuring the database failed. Couldn't create the database schema.
  java.sql.SQLException: No suitable driver found for localhost/confluence523?sessionVariables=storage_engine%3DInnoDB