qsslsocket_winrt.cpp defined it locally, which runs the risk of
clashes with a potential user-defined qHash(QSslError), so
make it public.
Also included both .error() and .certificate() in the hash, as
both of these are used to determine equality (the WinRT version
only used .error()).
[ChangeLog][QtNetwork][QSslError] Can now be used in QSet/QHash.
Change-Id: Ieb7995bed491ff011d4be9dad544248b56fd4f73
Reviewed-by: Oliver Wolff <oliver.wolff@digia.com>
Reviewed-by: Andrew Knight <andrew.knight@digia.com>