[gnome-builder] build: set bash completions dir to writable path

[Christian Hergert <chergert src gnome org>]

commit f8b9184632686eb5e83afecc2f29e20f7978e660
Author: Christian Hergert <chergert redhat com>
Date:   Tue Aug 29 03:27:24 2017 -0700

    build: set bash completions dir to writable path

 org.gnome.Builder.json |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/org.gnome.Builder.json b/org.gnome.Builder.json
index 75b77d7..eccd6f8 100644
--- a/org.gnome.Builder.json
+++ b/org.gnome.Builder.json
@@ -54,6 +54,7 @@
         "cflags": "-O2 -g",
         "cxxflags": "-O2 -g",
         "env": {
+            "BASH_COMPLETIONSDIR": "/app/share/bash-completion/completions",
             "MOUNT_FUSE_PATH": "../tmp/",
             "V": "1"
         }