common: by default, do not assert on leaks in the shared_cache code

common: by default, do not assert on leaks in the shared_cache code

Update the standard qa suite cluster configs so that we continue
asserting in our nightlies, but users don't hit this.

Fixes: http://tracker.ceph.com/issues/21737
Signed-off-by: Greg Farnum <gfarnum@redhat.com>
(cherry picked from commit 165b61a7df2731602e9e28c5107a873444bf0507)

Conflicts:
	src/common/options.cc - file does not exist in jewel; manually
                     backported the change to src/common/config_opts.h
        src/common/shared_cache.hpp - use jewel programming convention
                     for accessing config option values