Prevent Firefox from using apple-touch-icon (#10402)

* Prevent Firefox from using apple-touch-icon

The opaque background does not work well in Firefox which uses the icon
as a "rich icon". Prevent this by not specifying it in HTML. Real Apple
devices will still request the icon on the static path.

Fixes: https://github.com/go-gitea/gitea/issues/10394

Also adjust gitignore so app.ini.sample becomes searchable and fixed a
variable name in app.ini.sample.

* fix gitignore

templates/base/head.tmpl

@@ -96,7 +96,6 @@
 		};
 	</script>
 	<link rel="shortcut icon" href="{{StaticUrlPrefix}}/img/favicon.png">
-	<link rel="apple-touch-icon" href="{{StaticUrlPrefix}}/img/apple-touch-icon.png">
 	<link rel="mask-icon" href="{{StaticUrlPrefix}}/img/gitea-safari.svg" color="#609926">
 	<link rel="stylesheet" href="{{StaticUrlPrefix}}/vendor/assets/font-awesome/css/font-awesome.min.css">
 	<link rel="preload" as="font" href="{{StaticUrlPrefix}}/fomantic/themes/default/assets/fonts/icons.woff2" type="font/woff2" crossorigin="anonymous">