Bug#944490: Three different reported bugs

[Kurt Fitzner]

This is actually three different bugs.  Each of which have been 
reported:
#857791 postfixadmin & dbconfig-common: mysql/mysqli mismatch
#926253 Required smart cache directory not being created
#965075 postfixadmin: wrong alias in postfixadmin conf-available for 
apache2

I am cloning this bug and then merging the clones with the above.