Remove obsolete haveged and clean-apt from mysql

Element is carrying old install scripts that are not necessary.

Change-Id: Ie10bdb407781a8e2bf973b0635634326173b8701
Remove any accidental extra /etc/my.cnf

Some platforms have packages that install /etc/my.cnf which would not
work well with our element which wants the configs in /etc/mysql.

Change-Id: Ifda1cca7287fae37eb8587598f5fab60228d8e99