[gnome-builder] valgrind: fix null check of pipeline

[Christian Hergert <chergert src gnome org>]

commit c9f39d7ce8128bb7e36f83291a351b0b1135034f
Author: Günther Wagner <info gunibert de>
Date:   Thu Sep 20 19:59:24 2018 +0200

    valgrind: fix null check of pipeline

 src/plugins/valgrind/valgrind_plugin.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/plugins/valgrind/valgrind_plugin.py b/src/plugins/valgrind/valgrind_plugin.py
index a3bd5dd55..2b922f70f 100644
--- a/src/plugins/valgrind/valgrind_plugin.py
+++ b/src/plugins/valgrind/valgrind_plugin.py
@@ -46,7 +46,7 @@ class ValgrindWorkbenchAddin(GObject.Object, Ide.WorkbenchAddin):
         # When the pipeline changes, we need to check to see if we can find
         # valgrind inside the runtime environment.
         pipeline = build_manager.get_pipeline()
-        if pipeline:
+        if pipeline is not None:
             runtime = pipeline.get_configuration().get_runtime()
             if runtime and runtime.contains_program_in_path('valgrind'):
                 if not self.has_handler: