Bug 1078383: update gdbserver to 7.7 to fix the FD leak to the debugged process. r=mwu

Change-Id: I48bf5bfd966449108255a8b2ddc9d42d6ac023c1
Merge pull request #243 from CervantesYu/gdbserver-7.7

Bug 1078383: update gdbserver to 7.7 to fix the FD leak to the debugged ... r=mwu