[gnome-desktop-testing] Remove an unused variable

[Colin Walters <walters src gnome org>]

commit 0473e426b314c256950f481e9181207a1ed8b5a3
Author: Colin Walters <walters verbum org>
Date:   Tue May 15 15:33:09 2018 +0000

    Remove an unused variable
    
    This broke the libostree CI which builds g-d-t-r from
    git master using clang.

 src/gnome-desktop-testing-runner.c |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)
---
diff --git a/src/gnome-desktop-testing-runner.c b/src/gnome-desktop-testing-runner.c
index 03d94af..7ddaaaf 100644
--- a/src/gnome-desktop-testing-runner.c
+++ b/src/gnome-desktop-testing-runner.c
@@ -476,8 +476,6 @@ static void
 log_test_completion (GdtrTest *test,
                      const char *reason)
 {
-  const char *msgid_value;
-
   if (test->state == TEST_STATE_COMPLETE_SUCCESS)
     {
       test_log (TEST_LOG_ONE_SUCCESS, test->name, "PASS: %s", test->name);