Support swig3

From: David Rothenberger <daveroth@acm.org>

Fugly hack to fix build with SWIG 3.0.x.  The pre-processor seems to
expand the %define correctly with only the change to %{..%}, but
%extend still breaks somehow.

https://github.com/swig/swig/issues/379
---
 subversion/bindings/swig/svn_delta.i |    2 --
 1 file changed, 2 deletions(-)

diff --git a/subversion/bindings/swig/svn_delta.i b/subversion/bindings/swig/svn_delta.i
index f69b76e..4ad2718 100644
--- a/subversion/bindings/swig/svn_delta.i
+++ b/subversion/bindings/swig/svn_delta.i
@@ -206,8 +206,6 @@ void _ops_get(int *num_ops, const svn_txdelta_op_t **ops)
 
 #ifdef SWIGPYTHON
 %pythoncode %{
-# This function is for backwards compatibility only.
-# Use svn_txdelta_window_t.ops instead.
 svn_txdelta_window_t_ops_get = svn_txdelta_window_t._ops_get
 %}
 #endif
