[silx view] About page error
Trying to open the "About" page, I get the following error. I use Python 3.5.3 and PyQt 5.7:

```
ERROR:silx.gui.qt._qt:<class 'AttributeError'> 'QVBoxLayout' object has no attribute 'setMargin'   File "/home/retegan/.local/lib/python3.5/site-packages/silx/app/view.py", line 170, in about
    qtutils.About.about(self, "Silx viewer")
  File "/home/retegan/.local/lib/python3.5/site-packages/silx/app/qtutils.py", line 242, in about
    dialog = About(parent)
  File "/home/retegan/.local/lib/python3.5/site-packages/silx/app/qtutils.py", line 93, in __init__
    self.__createLayout()
  File "/home/retegan/.local/lib/python3.5/site-packages/silx/app/qtutils.py", line 100, in __createLayout
    layout.setMargin(0)
```

diff --git a/silx/app/qtutils.py b/silx/app/qtutils.py
index 1bf63b4f9..4c29c841d 100644
--- a/silx/app/qtutils.py
+++ b/silx/app/qtutils.py
@@ -1,6 +1,6 @@
 # coding: utf-8
 # /*##########################################################################
-# Copyright (C) 2016 European Synchrotron Radiation Facility
+# Copyright (C) 2016-2017 European Synchrotron Radiation Facility
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal
@@ -25,7 +25,7 @@
 
 __authors__ = ["V. Valls"]
 __license__ = "MIT"
-__date__ = "18/08/2017"
+__date__ = "22/09/2017"
 
 import sys
 
@@ -97,7 +97,6 @@ class About(qt.QDialog):
 
     def __createLayout(self):
         layout = qt.QVBoxLayout(self)
-        layout.setMargin(0)
         layout.setContentsMargins(24, 15, 24, 20)
         layout.setSpacing(8)
 
['silx/app/qtutils.py']