[gnome-shell] build: Use #!/bin/sh instead of #!/bin/bash

[Ting-Wei Lan <lantw src gnome org>]

commit 63f2fdd1a47c712a2f8cb3200338216e4dad9baf
Author: Ting-Wei Lan <lantw src gnome org>
Date:   Wed May 24 22:08:33 2017 +0800

    build: Use #!/bin/sh instead of #!/bin/bash
    
    There is no bashism in autogen.sh now.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=780215

 autogen.sh |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/autogen.sh b/autogen.sh
index 0734753..a73a427 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 # Run this to generate all the initial makefiles, etc.
 
 srcdir=`dirname $0`