multi_runsingle: move timestamp into INIT

Setting the TIMER_STARTSINGLE timestamp first in CONNECT has the
drawback that for actions that go back to the CONNECT state, the time
stamp is reset and for the multi_socket API there's no corresponding
Curl_expire() then so the timeout logic gets wrong!

Reported-by: Brad Spencer
Bug: http://curl.haxx.se/mail/lib-2014-02/0036.html