[gnome-builder] gradle: root build target under build system

[Christian Hergert <chergert src gnome org>]

commit d702726972eff1c7a7570dd9a36355d0a81438b6
Author: Christian Hergert <chergert redhat com>
Date:   Mon Jan 21 10:20:42 2019 -0800

    gradle: root build target under build system
    
    Forgot to set this when simplifying.

 src/plugins/gradle/gradle_plugin.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/plugins/gradle/gradle_plugin.py b/src/plugins/gradle/gradle_plugin.py
index 99536d8a0..59603e5c2 100755
--- a/src/plugins/gradle/gradle_plugin.py
+++ b/src/plugins/gradle/gradle_plugin.py
@@ -141,7 +141,7 @@ class GradleBuildTargetProvider(Ide.Object, Ide.BuildTargetProvider):
                                          code=Gio.IOErrorEnum.NOT_SUPPORTED))
             return
 
-        task.targets = [context.ensure_child_typed(GradleBuildTarget)]
+        task.targets = [build_system.ensure_child_typed(GradleBuildTarget)]
         task.return_boolean(True)
 
     def do_get_targets_finish(self, result):