ceph.spec.in: don't try to package __pycache__ for SUSE

ceph.spec.in: don't try to package __pycache__ for SUSE

When building on openSUSE Tumbleweed, nothing seems to create
the various __pycache__ directories (so the build fails because
those files don't exist), and in any case they should be
created automatically at runtime, so shouldn't need to be
packaged.  However, the Fedora packaging guidelines suggest
including __pycache__, so I've used a %suse_version guard here.

Fixes: http://tracker.ceph.com/issues/17106
Signed-off-by: Tim Serong <tserong@suse.com>