[gnome-builder] waf: fix shebang

[Christian Hergert <chergert src gnome org>]

commit 23a2e56a795bda46cd23d7a31be73a3154186687
Author: Christian Hergert <chergert redhat com>
Date:   Thu Mar 14 19:58:09 2019 -0700

    waf: fix shebang
    
    Fixes #847

 src/plugins/waf/waf_plugin.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/plugins/waf/waf_plugin.py b/src/plugins/waf/waf_plugin.py
index 25fa29490..1304a1f73 100644
--- a/src/plugins/waf/waf_plugin.py
+++ b/src/plugins/waf/waf_plugin.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env-python3
+#!/usr/bin/env python3
 
 #
 # waf_plugin.py