In cases where a cached ftp connection fails to connect, or a file
transfer has failed, we should removed the cached connection. Since qnam
has an idea of a single internal QFtp per full operation, when file
transfers failed previously the cached connection would be reused for
subsequent connections and thus fail.
[ChangeLog][QtNetwork][QNetworkAccessManager] QNetworkAccessManager now
properly handles FTP transfer failures by removing failed cached ftp
connections.
Task-number: QTBUG-40797
Change-Id: Ie090a39ceddd7e58a0d8baf7d01f2a08c70162e5
Reviewed-by: Richard J. Moore <rich@kde.org>