Fix race condition in a test

test1.63 was failing periodically due to a race condition. A signal
  was being sent to srun before the signal handler thread was spawned.

testsuite/expect/test1.63

@@ -72,6 +72,7 @@ expect {
 	}
 	-re "Hello World!" {
 		incr match_run
+		sleep 0.1
 		exec $bin_kill -INT $srun_pid
 		exp_continue
 	}