[libxml2] Try again to only build GitLab Pages on main repo

[Nick Wellnhofer <nwellnhof src gnome org>]

commit 0a6a79b21871cccaff059944d97ecaf93f83784f
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Sat Feb 12 21:36:27 2022 +0100

    Try again to only build GitLab Pages on main repo

 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 62955f4f..24e357ea 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -287,4 +287,4 @@ pages:
       - public/devhelp/Makefile*
       - public/devhelp/*.xsl
   only:
-    - master@gitlab-gnome-org/GNOME/libxml2
+    - master@GNOME/libxml2