wc: fix compilation against Subversion versions prior to 1.6.
wc: fix compilation against Subversion versions prior to 1.6.

The the `ret' local variable was referenced regardless of the version
of Subversion use, but only declared for 1.6 or later. Declaring it as
a PyObject in the pre-1.6 code allows compilation to proceed.

jelmer/subvertpy,jelmer/subvertpy