Do not overwrite SSL certificate config if it is already set for something other than the default location.
Do not overwrite SSL certificate config if it is already set for something
other than the default location.

(Bug #696817)  Patch by Dominik George <nik@naturalnet.de>

mswart/dovecot2deb,mswart/dovecot2deb,mswart/dovecot2deb,mswart/dovecot2deb,mswart/dovecot2deb