QPID-7306: fix regression in earlier commit

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1750390 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/qpid/cpp/src/qpid/broker/QueueRegistry.cpp b/qpid/cpp/src/qpid/broker/QueueRegistry.cpp
index c3cd348..987832c 100644
--- a/qpid/cpp/src/qpid/broker/QueueRegistry.cpp
+++ b/qpid/cpp/src/qpid/broker/QueueRegistry.cpp
@@ -133,8 +133,8 @@
         qpid::sys::RWlock::ScopedWlock locker(lock);
         QueueMap::iterator i = queues.find(name);
         if (i != queues.end()) {
-            q = i->second;
-            if (q->version == version) {
+            if (i->second->version == version) {
+                q = i->second;
                 eraseLH(i, q, name, connectionId, userId);
             }
         }