connect: Check that errno is 0 to fix Windows build.
connect: Check that errno is 0 to fix Windows build.

Thanks to Viktor Butskih.

Signed-off-by: Andreas Schneider <5be00ddc76278cf6077f5047ca3384a88460c671@cryptomilk.org>
(cherry picked from commit e051135a0516f686456b9f3d089f91ded177ef1a)

mwgoldsmith/ssh,mwgoldsmith/ssh,mwgoldsmith/ssh,mwgoldsmith/libssh,mwgoldsmith/libssh,mwgoldsmith/libssh,mwgoldsmith/libssh,mwgoldsmith/ssh