This is an attempt to amelioriate the situation found in #2384 where
we see the cURL connect() failing to complete. Based on the pcap
from the bug log, we believe that RISC OS is likely failing to signal
the completion of the connection to cURL. As such, cURL times out.
This change permits retries of timed out connections in the hope that
a fresh socket FD might subsequently function correctly. The defaults
chosen mean that the previous behaviour of 30 seconds before timeout
is reported will remain the same, but in that time we will make 3 separate
attempts to connect the socket.
