(svn r22693) -Fix [FS#4691]: The override managers were not reset in some cases like creating a new scenario.

src/newgrf.h

@@ -162,6 +162,7 @@ void LoadNewGRFFile(struct GRFConfig *config, uint file_index, GrfLoadingStage s
 void LoadNewGRF(uint load_index, uint file_index);
 void ReloadNewGRFData(); // in saveload/afterload.cpp
 void ResetNewGRFData();
+void ResetPersistentNewGRFData();
 
 void CDECL grfmsg(int severity, const char *str, ...) WARN_FORMAT(2, 3);