[polari] app: Stop tracking about dialog

[Florian Müllner <fmuellner src gnome org>]

commit 2f2b7a399085a317eda485516dde105a440894f3
Author: Florian Müllner <fmuellner gnome org>
Date:   Fri Jan 15 21:53:05 2021 +0100

    app: Stop tracking about dialog
    
    The `about` action used to be exposed in the (external) app menu,
    so it was reasonable to handle the case where it was activated
    with the dialog already showing.
    
    But now that the menu is gone, the only UI to bring up the dialog
    is blocked by the dialog itself.
    
    https://gitlab.gnome.org/GNOME/polari/-/merge_requests/174

 src/application.js | 12 ++----------
 1 file changed, 2 insertions(+), 10 deletions(-)
---
diff --git a/src/application.js b/src/application.js
index 5b40ca70..7c36108c 100644
--- a/src/application.js
+++ b/src/application.js
@@ -801,10 +801,6 @@ var Application = GObject.registerClass({
     }
 
     _onShowAbout() {
-        if (this._aboutDialog) {
-            this._aboutDialog.present();
-            return;
-        }
         let aboutParams = {
             authors: [
                 'Florian Müllner <fmuellner gnome org>',
@@ -844,12 +840,8 @@ var Application = GObject.registerClass({
             modal: true,
         };
 
-        this._aboutDialog = new Gtk.AboutDialog(aboutParams);
-        this._aboutDialog.show();
-        this._aboutDialog.connect('response', () => {
-            this._aboutDialog.destroy();
-            this._aboutDialog = null;
-        });
+        const aboutDialog = new Gtk.AboutDialog(aboutParams);
+        aboutDialog.show();
     }
 
     _onQuit() {