[gnome-builder] diagnostics: remove overzealous assertion

[Christian Hergert <chergert src gnome org>]

commit 6823a24a660f136a10a7007a5f5d0e56a873e2b7
Author: Christian Hergert <chergert redhat com>
Date:   Mon Nov 28 16:11:18 2016 -0800

    diagnostics: remove overzealous assertion
    
    Turns out we can hit this path, I just did.

 libide/diagnostics/ide-diagnostics-manager.c |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)
---
diff --git a/libide/diagnostics/ide-diagnostics-manager.c b/libide/diagnostics/ide-diagnostics-manager.c
index 60b641c..f463e5f 100644
--- a/libide/diagnostics/ide-diagnostics-manager.c
+++ b/libide/diagnostics/ide-diagnostics-manager.c
@@ -918,8 +918,6 @@ ide_diagnostics_manager_update_group_by_file (IdeDiagnosticsManager *self,
         }
     }
 
-  g_assert_not_reached ();
-
   IDE_EXIT;
 }