Make file manager a bit less verbose, it's normal that createXMLTree does not always find the file

git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/trunk@7453 178a84e3-b1eb-0310-8ba1-8eac791a3b58

src/io/file_manager.cpp

@@ -237,8 +237,11 @@ XMLNode *FileManager::createXMLTree(const std::string &filename)
         return node;
     }
     catch (std::runtime_error& e)
+    {
+        if (UserConfigParams::m_verbosity >= 3)
         {
             fprintf(stderr, "[FileManager::createXMLTree] %s\n", e.what());
+        }
         return NULL;
     }
 }   // getXMLTree