Fix crash if try to expand dirble and --no-network passed to Cantata.

ChangeLog

@@ -33,6 +33,7 @@
 25. Allow adding Jamendo/Magnatune tracks to stored playlists.
 26. Add "--collection" commandline option to control the initial collection to
     use.
+27. Fix crash if try to expand dirble and --no-network passed to Cantata.
 
 2.3.0
 -----

gui/apikeys.cpp

@@ -140,6 +140,9 @@ bool ApiKeys::isLimitReached(const QNetworkReply *job, Service srv)
     if (isLimitReached(srv)) {
         return true;
     }
+    if (!job) {
+        return false;
+    }
 
     bool reached = false;
     switch (srv) {