The qwebsocketprotocol.h header does not declare any class, but only a
namespace. This patch updates sync.profile by declaring 'classnames'
with QWebSocketProtocol explicitly.

Task-number: QTBUG-58651
Change-Id: I759b34c227b3d6ca970bcff08c6fdcbafb958c9e
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@qt.io>