[gnome-continuous] Add libgd again

[Jeremy Bicha <jbicha src gnome org>]

commit 2570ee307f4a2f751fc8dc04c8c484a4262b7dbc
Author: Jeremy Bicha <jbicha ubuntu com>
Date:   Sun Oct 7 22:52:45 2018 -0400

    Add libgd again

 manifest.json | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/manifest.json b/manifest.json
index c3b5b64..c1aac3f 100644
--- a/manifest.json
+++ b/manifest.json
@@ -1272,6 +1272,9 @@
                {"src": "gnome:gspell.git",
                  "name": "gspell"},
 
+                {"src": "gnome:libgd.git",
+                 "name": "libgd"},
+
                {"src": "gnome:gedit.git",
                  "name": "gedit"},