Wrong warning fixed

src/factor/factor_base.cpp

@@ -157,7 +157,7 @@ void FactorBase::link(FeatureBasePtr _ftr_ptr)
     this->setFeature(_ftr_ptr);
 
     // set problem ( and register factor )
-    WOLF_WARN_COND(this->getProblem() == nullptr, "ADDING FACTOR ", this->id(), " TO FEATURE ", _ftr_ptr->id(), " NOT CONNECTED WITH PROBLEM.");
+    WOLF_WARN_COND(_ftr_ptr->getProblem() == nullptr, "ADDING FACTOR ", this->id(), " TO FEATURE ", _ftr_ptr->id(), " THAT IS NOT CONNECTED WITH PROBLEM.");
     this->setProblem(_ftr_ptr->getProblem());
 
     // constrained by