configure: hint that 'mysqlclient' can provide the 'mysql_init' symbol
Ubuntu has 'default-libmysqlclient-dev' pointing to mysql instead of mariadb. This additional hint helps the build system figure out how to link table-mysql. For some reason, the mysql_config based fallback ended up providing the right arguments, but at the wrong place (before the objects files in the command line). I did not investigate further how to fix that fallback mode.
Edited by Florent 'Skia' Jacquet