plugin XEP-0054: removed Image.ANTIALIAS filter:

Image.ANTIALIAS filter is not needed anymore in Pillow: http://pillow.readthedocs.io/en/3.0.x/releasenotes/2.7.0.html#default-filter-for-thumbnails

src/plugins/plugin_xep_0054.py

@@ -445,7 +445,7 @@ class XEP_0054(object):
             return Failure(exceptions.DataError(u"Can't open image"))
 
         if img.size != AVATAR_DIM:
-            img.thumbnail(AVATAR_DIM, Image.ANTIALIAS)
+            img.thumbnail(AVATAR_DIM)
             if img.size[0] != img.size[1]:  # we need to crop first
                 left, upper = (0, 0)
                 right, lower = img.size