Change the toggle-player toolbar item icon

Since some recent versions of Adwaita, action icons on the toolbar are now
symbolic. This one icon broke that consistency, probably because we were
misusing a mimetype icon there and no symbolic versions of those are available.
Hopefully this works with other themes too, haven't tested.

NEWS.md

@@ -1,3 +1,9 @@
+PENDING: Gaupol 1.14
+====================
+
+* Change the icon for the toggle video player toolbar item to an action
+  icon (not mimetype) that has a symbolic version available
+
 2023-10-08: Gaupol 1.13
 =======================
 

gaupol/application.py

@@ -276,7 +276,7 @@ def _init_main_toolbar(self, vbox):
         self.main_toolbar.insert(button, -1)
         # win.toggle-player
         button = Gtk.ToggleToolButton(
-            label=_("Video"), icon_name="video-x-generic")
+            label=_("Video"), icon_name="camera-video")
         button.set_action_name("win.toggle-player")
         button.set_tooltip_text(_("Show or hide the video player"))
         self.main_toolbar.insert(button, -1)