[tracker/tracker-2.3] ci: Fix tests with Fedora 31 container image

[Sam Thursfield <sthursfield src gnome org>]

commit 60db951baaba8736a61c51da748b555164a0546e
Author: Sam Thursfield <sam afuera me uk>
Date:   Wed Dec 11 15:06:59 2019 +0100

    ci: Fix tests with Fedora 31 container image
    
    Backport of https://gitlab.gnome.org/GNOME/tracker/merge_requests/163

 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 87e32d5ee..8a15ace67 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -15,7 +15,7 @@ test-fedora-latest:
       # screenful of junk each time unless we strip these.
       unset $(env|grep -o '^CI_[^=]*')
 
-      su tracker -c 'cd build; meson test --print-errorlogs'
+      su tracker -c 'cd build; env LANG=C.UTF8 LC_ALL=C.UTF8 meson test --print-errorlogs'
 
   artifacts:
     when: always