server.current_client fix and minor refactoring.

Thanks to @codeslinger (Toby DiPasquale) for identifying the issue.

Related to issue #2409.

src/blocked.c

@@ -118,9 +118,7 @@ void processUnblockedClients(void) {
 
         /* Process remaining data in the input buffer. */
         if (c->querybuf && sdslen(c->querybuf) > 0) {
-            server.current_client = c;
             processInputBuffer(c);
-            server.current_client = NULL;
         }
     }
 }