TransportHttp: abort on time-out or on SocketException

TransportHttp: abort on time-out or on SocketException

Avoid trying other authentication methods on SocketException or on
InterruptedIOException. SocketException is rather fatal, such as
nothing listening on the peer's port, connection reset, or it could
be a connection time-out.

Time-outs enforced by Timeout{Input,Output}Stream may result in
InterruptedIOException being thrown.

In both cases, it makes no sense to try other authentication methods,
and doing so may wrongly report "authentication not supported" or
"cannot open git-upload-pack" or some such instead of reporting a
time-out.

Bug: 563138
Change-Id: I0191b1e784c2471035e550205abd06ec9934fd00
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>