Remove relcache entry invalidation in REFRESH MATERIALIZED VIEW.
Remove relcache entry invalidation in REFRESH MATERIALIZED VIEW.

This was added as part of the attempt to support unlogged matviews
along with a populated status.  It got missed when unlogged
support was removed pre-commit.

Noticed by Noah Misch.  Back-patched to 9.3 branch.

lisakowen/gpdb,adam8157/gpdb,xinzweb/gpdb,Postgres-XL/Postgres-XL,zeroae/postgres-xl,50wu/gpdb,techdragon/Postgres-XL,jmcatamney/gpdb,xinzweb/gpdb,lisakowen/gpdb,jmcatamney/gpdb,techdragon/Postgres-XL,Postgres-XL/Postgres-XL,ashwinstar/gpdb,adam8157/gpdb,greenplum-db/gpdb,techdragon/Postgres-XL,yazun/postgres-xl,pavanvd/postgres-xl,ashwinstar/gpdb,adam8157/gpdb,50wu/gpdb,50wu/gpdb,ovr/postgres-xl,50wu/gpdb,jmcatamney/gpdb,lisakowen/gpdb,adam8157/gpdb,greenplum-db/gpdb,greenplum-db/gpdb,greenplum-db/gpdb,ovr/postgres-xl,oberstet/postgres-xl,greenplum-db/gpdb,xinzweb/gpdb,50wu/gpdb,jmcatamney/gpdb,techdragon/Postgres-XL,oberstet/postgres-xl,yazun/postgres-xl,lisakowen/gpdb,Postgres-XL/Postgres-XL,adam8157/gpdb,ovr/postgres-xl,pavanvd/postgres-xl,ashwinstar/gpdb,50wu/gpdb,oberstet/postgres-xl,jmcatamney/gpdb,Postgres-XL/Postgres-XL,ashwinstar/gpdb,ashwinstar/gpdb,greenplum-db/gpdb,xinzweb/gpdb,yazun/postgres-xl,pavanvd/postgres-xl,lisakowen/gpdb,greenplum-db/gpdb,zeroae/postgres-xl,jmcatamney/gpdb,50wu/gpdb,yazun/postgres-xl,zeroae/postgres-xl,lisakowen/gpdb,ovr/postgres-xl,adam8157/gpdb,jmcatamney/gpdb,jmcatamney/gpdb,greenplum-db/gpdb,oberstet/postgres-xl,techdragon/Postgres-XL,50wu/gpdb,Postgres-XL/Postgres-XL,ashwinstar/gpdb,yazun/postgres-xl,adam8157/gpdb,ashwinstar/gpdb,oberstet/postgres-xl,adam8157/gpdb,ashwinstar/gpdb,pavanvd/postgres-xl,xinzweb/gpdb,zeroae/postgres-xl,ovr/postgres-xl,pavanvd/postgres-xl,xinzweb/gpdb,zeroae/postgres-xl,lisakowen/gpdb,lisakowen/gpdb,xinzweb/gpdb,xinzweb/gpdb