Don't allow inactive sync providers (like gtasks) to sync in background

api/src/com/todoroo/astrid/sync/SyncV2BackgroundService.java

@@ -77,13 +77,15 @@ abstract public class SyncV2BackgroundService extends Service {
         if(!getSyncUtilities().isLoggedIn())
             return;
 
-        getSyncProvider().synchronizeActiveTasks(false, new SyncResultCallbackAdapter() {
+        SyncV2Provider provider = getSyncProvider();
-            @Override
+        if (provider.isActive())
-            public void finished() {
+            provider.synchronizeActiveTasks(false, new SyncResultCallbackAdapter() {
-                getSyncUtilities().recordSuccessfulSync();
+                @Override
-                context.sendBroadcast(new Intent(AstridApiConstants.BROADCAST_EVENT_REFRESH));
+                public void finished() {
-            }
+                    getSyncUtilities().recordSuccessfulSync();
-        });
+                    context.sendBroadcast(new Intent(AstridApiConstants.BROADCAST_EVENT_REFRESH));
+                }
+            });
     }
 
     @Override