Codechange: use separate pre and post callbacks for int settings

src/elrail.cpp

@@ -593,9 +593,9 @@ void DrawRailCatenary(const TileInfo *ti)
 	DrawRailCatenaryRailway(ti);
 }
 
-bool SettingsDisableElrail(int32 p1)
+void SettingsDisableElrail(int32 new_value)
 {
-	bool disable = (p1 != 0);
+	bool disable = (new_value != 0);
 
 	/* we will now walk through all electric train engines and change their railtypes if it is the wrong one*/
 	const RailType old_railtype = disable ? RAILTYPE_ELECTRIC : RAILTYPE_RAIL;
@@ -639,5 +639,4 @@ bool SettingsDisableElrail(int32 p1)
 	 * rails. It may have unintended consequences if that function is ever
 	 * extended, though. */
 	ReinitGuiAfterToggleElrail(disable);
-	return true;
 }