Document 'svn_*_change_rev_prop2' as a known non-ouput 'type **' param.
For issue "swig-py change_rev_prop2() crashes".
Known instances of "type **" which are *not* OUTPUT parameters are:
- svn_stream_checksummed(..., const unsigned char **read_digest,
const unsigned char **write_digest, ...)
+ - svn_*_change_rev_prop2(..., const svn_string_t *const *old_value_p, ...)
*/
%typemap(in, numinputs=0) SWIGTYPE ** ($*1_ltype temp) "$1 = &temp;";
