[gnome-tweak-tool] autostart: don't add trailing space

[Jeremy Bicha <jbicha src gnome org>]

commit 4bd9ea4e1e4ffa5d5c384ca7c4015995d775dc7a
Author: Jeremy Bicha <jbicha ubuntu com>
Date:   Tue May 30 00:48:23 2017 -0400

    autostart: don't add trailing space

 gtweak/utils.py |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/gtweak/utils.py b/gtweak/utils.py
index 607570b..64b07aa 100644
--- a/gtweak/utils.py
+++ b/gtweak/utils.py
@@ -151,7 +151,10 @@ class AutostartFile:
             raise Exception("Need either an appinfo or a file name")
 
         self._exec_cmd = exec_cmd
-        self._extra_exec_args = " %s\n" % extra_exec_args
+        if extra_exec_args:
+            self._extra_exec_args = " %s\n" % extra_exec_args
+        else:
+            self._extra_exec_args = "\n"
 
         user_autostart_dir = os.path.join(GLib.get_user_config_dir(), "autostart")
         if not os.path.isdir(user_autostart_dir):