Fix bug where we erroneously answer queries belonging to another shard

Author: JohnSully

src/cluster.cpp

@@ -5991,7 +5991,7 @@ clusterNode *getNodeByQuery(client *c, struct redisCommand *cmd, robj **argv, in
                 /* If it is not the first key, make sure it is exactly
                  * the same key as the first we saw. */
                 if (!equalStringObjects(firstkey,thiskey)) {
-                    clusterNode* nThisKey = g_pserver->cluster->slots[slot];
+                    clusterNode* nThisKey = g_pserver->cluster->slots[thisslot];
 
                     if ((slot != thisslot) && (nThisKey != n || migrating_slot || importing_slot || g_pserver->cluster->migrating_slots_to[slot] != nullptr || g_pserver->cluster->importing_slots_from[slot] != nullptr)) {
                         /* Error: multiple keys from different slots. */