Remove a stray, no-longer-used needle

This was part of a workaround for a Fedora Atomic Workstation
(old name for Silverblue) issue that got resolved a while back;
we forgot to take the needle out.

Signed-off-by: Adam Williamson <awilliam@redhat.com>

needles/gnome/desktop_auth_required-gnome.json

@@ -1,16 +0,0 @@
-{
-  "tags": [
-    "DESKTOP-gnome",
-    "desktop_auth_required"
-  ],
-  "area": [
-    {
-      "xpos": 593,
-      "ypos": 521,
-      "width": 86,
-      "height": 16,
-      "type": "match"
-    }
-  ],
-  "properties": []
-}