hotfix: remove outdated ISO warning when not in ISO

previously welcome would show an outdated ISO warning popup even when
not in ISO and the user clicked on the about button. This commit removes
the outdated ISO warning popup when not in ISO.

Signed-off-by: SoulHarsh007 <harsh.peshwani@outlook.com>

Author: SoulHarsh007

src/main.rs

@@ -567,7 +567,6 @@ fn on_action_clicked(param: &[glib::Value]) -> Option<glib::Value> {
             None
         },
         _ => {
-            outdated_version_check(fl!("calamares-install-type"));
             show_about_dialog();
             None
         },