Remove database user/password config, use full URL

Configuration of User/Password of database has been removed, favouring the use
of a fully qualified JDBC URL with user and password. For example, in MySQL,
DATABASE_URL should be something like:

    jdbc:mysql://localhost/smartdrugsearch?user=sds&password=sds
Fix database configuration key mistake

Previous commit deleted database.url instead of database.password. This commit
fixes it.