[gnome-builder] vala-pack: implement new vfunc for pipeline addin

[Christian Hergert <chergert src gnome org>]

commit 51ca0bbf04478d1161c7ceb8623e9c51e343de90
Author: Christian Hergert <chergert redhat com>
Date:   Fri Mar 29 17:36:01 2019 -0700

    vala-pack: implement new vfunc for pipeline addin

 src/plugins/vala-pack/ide-vala-pipeline-addin.vala | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/src/plugins/vala-pack/ide-vala-pipeline-addin.vala 
b/src/plugins/vala-pack/ide-vala-pipeline-addin.vala
index 7f1db3870..f7fd25ef1 100644
--- a/src/plugins/vala-pack/ide-vala-pipeline-addin.vala
+++ b/src/plugins/vala-pack/ide-vala-pipeline-addin.vala
@@ -33,6 +33,10 @@ namespace Ide
 
                uint error_format = 0;
 
+               public void prepare (Ide.Pipeline pipeline)
+               {
+               }
+
                public void load (Ide.Pipeline pipeline)
                {
                        this.error_format = pipeline.add_error_format (ERROR_FORMAT_REGEX,