If gdb was disconnected by the moment the target entered halted state, update_halt_gdb would segfault. Change-Id: I67477e9199c1df097be83a49e38602f975c083f5 Reported-by: Younes REGAIEG <younes.regaieg@imag.fr> Signed-off-by: Paul Fertser <fercerpav@gmail.com> Reviewed-on: http://openocd.zylin.com/2098 Tested-by: jenkins Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>tags/v0.8.0-rc2