App: [skip ci] AddressSanitizer: heap-use-after-free

When removing a dynamic property its myName member must be nullified as the memory has been de-allocated

src/App/DynamicProperty.cpp

@@ -217,6 +217,8 @@ bool DynamicProperty::removeDynamicProperty(const char* name)
         GetApplication().signalRemoveDynamicProperty(*prop);
         Property::destroy(prop);
         index.erase(it);
+        // memory of myName has been freed
+        prop->myName = nullptr;
         return true;
     }