Catch all std::exception when loading a map

Since 0eed117e6d exceptions from the map generation script are rethrown
in the main thread but not all of them are catched.

source/main.cpp

@@ -333,7 +333,7 @@ static int ProgressiveLoad()
 			break;
 		}
 	}
-	catch (PSERROR_Game_World_MapLoadFailed& e)
+	catch (std::exception& e)
 	{
 		// Map loading failed