py3: define __next__ in patch.py
This needed to appease Python 3's iterator protocol.
This is crasher #5 in Python 3.
Differential Revision: https://phab.mercurial-scm.org/D1480
--- a/mercurial/patch.py Mon Nov 20 23:02:32 2017 -0800
+++ b/mercurial/patch.py Mon Nov 20 23:13:09 2017 -0800
@@ -149,6 +149,8 @@
raise StopIteration
return l
+ __next__ = next
+
inheader = False
cur = []