Only call chkconfig --del if this is an uninstall and not an upgrade

During an RPM upgrade, operations run in the following order:

%pre
<install new version>
%post
%preun
<uninstall old version>
%postun

So %preun shouldn't call chkconfig --del in an upgrade (i.e. when $1 =
1)

Signed-off-by: Akshay <akshay.ramani@citrix.com>
Merge pull request #1 from akshayramani/SCTX-1696

SCTX-1696: Only call chkconfig --del if this is an uninstall and not an upgrade