message: Fix a debug assertion
diff: @@ -19847,6 +19847,7 @@ void CvGameTextMgr::setTradeRouteHelp(CvWStringBuffer &szBuffer, int iRoute, CvC
  {
  szBuffer.append(NEWLINE);
  szBuffer.append(gDLL->getText("TXT_KEY_TRADE_ROUTE_MOD_DEFENSIVE_PACT", iNewMod));
  + iModifier += iNewMod;
  }
  }
  