[glade] GNOME Bugzilla has been replaced by GNOME Gitlab

[Andre Klapper <aklapper src gnome org>]

commit bfd3020f6632f1a6a61710fdfb8018e48986c590
Author: Andre Klapper <a9016009 gmx de>
Date:   Sat Sep 15 12:34:22 2018 +0200

    GNOME Bugzilla has been replaced by GNOME Gitlab

 help/C/index.docbook | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/help/C/index.docbook b/help/C/index.docbook
index 327ec4e9..55340889 100644
--- a/help/C/index.docbook
+++ b/help/C/index.docbook
@@ -459,8 +459,8 @@ copies.</para>
     <para>
       To report a bug or make a suggestion regarding this application or
       this manual, you can submit them using 
-      <ulink url="http://bugzilla.gnome.org/enter_bug.cgi?product=glade3"; 
-       type="http">bugzilla</ulink>.
+      <ulink url="https://gitlab.gnome.org/GNOME/glade/issues/"; 
+       type="http">our issue tracking system</ulink>.
     </para>
 
     <para>