Adds HASH_STRINGS flag to ruleutils_14.c
Adds HASH_STRINGS flag to ruleutils_14.c

Relevant PG commit:
b3817f5f774663d55931dd4fab9c5a94a15ae7ab

citusdata/citus,citusdata/citus,citusdata/citus,citusdata/citus,citusdata/citus