Init lastWrite and date for campaigns

lib/mapping/CMapInfo.cpp

@@ -78,6 +78,8 @@ void CMapInfo::campaignInit()
 	originalFileURI = resource.getOriginalName();
 	fullFileURI = boost::filesystem::canonical(*CResourceHandler::get()->getResourceName(resource)).string();
 	campaign = CampaignHandler::getHeader(fileURI);
+	lastWrite = boost::filesystem::last_write_time(*CResourceHandler::get()->getResourceName(resource));
+	date = TextOperations::getFormattedDateTimeLocal(lastWrite);
 }
 
 void CMapInfo::countPlayers()