[polari/gnome-3-22] Update .gitignore

[Florian Müllner <fmuellner src gnome org>]

commit 82184ca746c85e76ec730228399b8f0feb5eebc3
Author: Florian Müllner <fmuellner gnome org>
Date:   Sun Feb 19 01:24:42 2017 +0100

    Update .gitignore
    
    Since commit 562164546, build-aux/ contains non-generated files
    under the flatpak/ subdirectory, so "unignore" that.

 .gitignore |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/.gitignore b/.gitignore
index ddee6d9..23669c0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -15,7 +15,8 @@ Makefile
 Makefile.in
 aclocal.m4
 autom4te.cache/
-build-aux/
+build-aux/*
+!build-aux/flatpak
 config.*
 configure
 data/appdata/*.appdata.valid