Resolve "Firefox app icon not updated"

Closes #558 (closed)

aleksis/core/apps.py

@@ -97,15 +97,16 @@ class CoreConfig(AppConfig):
             if name in ("primary", "secondary"):
                 clean_scss()
             elif name in ("favicon", "pwa_icon"):
-                from favicon.models import Favicon  # noqa
+                from favicon.models import Favicon, FaviconImg  # noqa
 
                 is_favicon = name == "favicon"
 
                 if new_value:
-                    Favicon.on_site.update_or_create(
+                    favicon_id = Favicon.on_site.update_or_create(
                         title=name,
                         defaults={"isFavicon": is_favicon, "faviconImage": new_value},
-                    )
+                    )[0]
+                    FaviconImg.objects.filter(faviconFK=favicon_id).delete()
                 else:
                     Favicon.on_site.filter(title=name, isFavicon=is_favicon).delete()
                     if name in settings.DEFAULT_FAVICON_PATHS: