sslutil: move sslkwargs logic into internal function (API)
As the previous commit documented, sslkwargs() doesn't add any
value since its return is treated as a black box and proxied
to wrapsocket().
We formalize its uselessness by moving its logic into a
new, internal function and make sslkwargs() return an empty
dict.
The certificate arguments that sslkwargs specified have been
removed from wrapsocket() because they should no longer be
set.
https://bz.mercurial-scm.org/1089
$ hg init
$ mkdir a
$ echo a > a/b
$ hg ci -Am m
adding a/b
$ hg rm a
removing a/b (glob)
$ hg ci -m m a
$ mkdir a b
$ echo a > a/b
$ hg ci -Am m
adding a/b
$ hg rm a
removing a/b (glob)
$ cd b
Relative delete:
$ hg ci -m m ../a
$ cd ..