Restore behavior of disabling address randomization by default on GDBserver

Restore behavior of disabling address randomization by default on GDBserver

Commit

  c12a508 ("Add client_state struct.")

inadvertently changed the default behavior of GDBserver wrt address
randomization.  The old disable_randomization global variable was
initialized to 1, whereas the corresponding field in the client_state
structure is initialized to 0.

This fixes

  make check TESTS="gdb.base/jit-simple.exp" RUNTESTFLAGS="--target_board=native-gdbserver"
  make check TESTS="gdb.base/execl-update-breakpoints.exp" RUNTESTFLAGS="--target_board=native-gdbserver"

Note that the execl-update-breakpoints.exp would only fail on systems
where the toolchain emits position-independent executables by default
(otherwise the main executable position is never randomized, so the
value of disable_randomization didn't matter).

gdb/gdbserver/ChangeLog:

	PR gdb/23374
	PR gdb/23375
	* server.h (struct client_state) <disable_randomization>:
	Initialize to 1.