Fix a typo in logicalrep_write_typ().

Author: ChangAo Chen
Discussion: https://postgr.es/m/tencent_CDECB843B30A8B6B5152FA6458F0F00FDE09@qq.com

Author: Amit Kapila

src/backend/replication/logical/proto.c

@@ -739,7 +739,7 @@ logicalrep_write_typ(StringInfo out, TransactionId xid, Oid typoid)
 		elog(ERROR, "cache lookup failed for type %u", basetypoid);
 	typtup = (Form_pg_type) GETSTRUCT(tup);
 
-	/* use Oid as relation identifier */
+	/* use Oid as type identifier */
 	pq_sendint32(out, typoid);
 
 	/* send qualified type name */