Removed Login Error if Blackboard is unavailable

app/src/main/java/de/sebse/fuplanner/services/fulogin/UserLoginTask.java

@@ -85,8 +85,10 @@ public class UserLoginTask extends AsyncTask<Void, Void, String> {
                             // Blackboard never used
                             success.setNotAvailable();
                             login.set(success.toJsonString());
-                        }
+                            latch.countDown();
+                        } else {
                             errorFunc.onError(error);
+                        }
                     });
                 }, errorFunc);
                 break;