cmake: fix krb5 detection on SUSE

`zypper install krb5-devel` installs executables outside of $PATH.
It also installs /etc/profile.d/krb5.sh that is sourced by a new
shell to add the new location to the $PATH. But this doesn't affect
the current shell.

Now decent Linux distros remind the user to run `. /etc/profile`
to reload paths in such a case. SUSE doesn't and for a good reason -
it doesn't work there. Because SUSE sets PROFILEREAD=true in the
environment and /etc/profile does not do anything.

By this point, one should not really expect `unset PROFILEREAD` to help,
and it does not - PROFILEREAD is readonly, and cannot be unset.

Apparently SUSE really *really* wants you to re-login between installing
MariaDB build dependencies and actually running the rpmbuild.

Which we cannot do it buildbot. And it would look very user-un-friendly
in the Build Instructions section of the manual.

So, we work around it - by adding SUSE krb5 path to the search list.

THIS IS SUSEEEEEE!!!

plugin/auth_gssapi/cmake/FindGSSAPI.cmake

@@ -40,7 +40,7 @@ if(GSSAPI_LIBS AND GSSAPI_FLAVOR)
 else(GSSAPI_LIBS AND GSSAPI_FLAVOR)
 
   find_program(KRB5_CONFIG NAMES krb5-config heimdal-krb5-config PATHS
-     /opt/local/bin
+     /opt/local/bin /usr/lib/mit/bin
      ONLY_CMAKE_FIND_ROOT_PATH               # this is required when cross compiling with cmake 2.6 and ignored with cmake 2.4, Alex
   )
   mark_as_advanced(KRB5_CONFIG)