server: keep a ref on the client context while clearing up
server: keep a ref on the client context while clearing up

We need to keep a ref on the client context struct for the duration of
the cleanup otherwise it will be disposed of before the
SoupSocket::disconnect callback is called, and that will dereference
the old client context pointer.

Fixes: https://bugzilla.gnome.org/show_bug.cgi?id=673468

Signed-off-by: Jonny Lamb <54cd04502facfcf96b325c60af9b1611ee761860@gnome.org>

jwendell/libsoup,fanc999/libsoup,Distrotech/libsoup,jwendell/libsoup,fanc999/libsoup,fanc999/libsoup,Distrotech/libsoup,Distrotech/libsoup,jwendell/libsoup,fanc999/libsoup,Distrotech/libsoup,fanc999/libsoup,Distrotech/libsoup,jwendell/libsoup,jwendell/libsoup