[gnome-build-meta/staging-3-30] Update bst-external to 0.5.0

[Jordan Petridis <jpetridis src gnome org>]

commit c9c4a8d79a89c7275eeb22ac9de37b748a747893
Author: Jordan Petridis <jpetridis gnome org>
Date:   Wed Sep 19 21:35:04 2018 +0300

    Update bst-external to 0.5.0

 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 5693485..ab6dcfd 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -5,7 +5,7 @@ variables:
   GET_SOURCES_ATTEMPTS: 3
   BST: "bst --config build.conf --log-file logs/build.log --colors"
   BST_SHA: '301a393cb6499b3f869d74827a9e8dc61b97d00e' #  1.1.7
-  BST_EXTERNAL_SHA: '1622d57dfbde94f6cee84e1d8dfd430c86040251' # 0.3.1
+  BST_EXTERNAL_SHA: 'ab9b37b5b52a7b2f62ddf17a68b76512da538291' # 0.5.0
   OSTREE_PUSH_SHA: '9aa82b67325786a810653155b952a17b7ccc436a'
   FLATPAK_BRANCH: "3.30"
   FLATPAK_SERVER_ADDRESS: 'gbm.gnome.org'