Fix r14945: Fixed Write.cc:41 "!ccb->active()" assertion.

Fix r14945:  Fixed Write.cc:41 "!ccb->active()" assertion.

The r14945 patch has a major bug:
 When the Http::One::Server::writeControlMsgAndCall fails to write the control
message, schedules a Comm::Write callback using just a ScheduleCallHere command.
The callback called withtout the CommIoCbParams details and squid is crashes.

This patch fixes the ConnStateData::writeControlMsgAndCall to return false if it
fails to write the control message and allow the caller to handle the failure.

This is a Measurement Factory project