lazutils: GetLCLWidgetType falls back to build platform not gtk2

lazbuild links no widgetset, so its CreateDefaults hit the hardcoded
gtk2 fallback and baked GTK into fresh build profiles - showing GTK as
the Build Lazarus widget type on Windows. on Linux the build platform is
gtk2 too, so no change there.

Author: fibodevy

components/lazutils/lazversion.pas

@@ -112,7 +112,9 @@ function GetLCLWidgetType: TLCLPlatform;
   if Assigned(OnLCLWidgetType) then
     Result := OnLCLWidgetType()
   else
-    Result := lpGtk2;
+    // no running widgetset (e.g. lazbuild): fall back to the platform this
+    // binary was built for, not a hardcoded gtk2
+    Result := GetBuildLCLWidgetType;
 end;
 
 function GetLCLWidgetTypeName: string;