test-serve: let run-tests.py kill the daemons

If the daemons die while the tests are still running, we'll get additional
"killed!" messages, making the test fail.

tests/test-serve

@@ -5,8 +5,8 b' cd test'
 
 echo % Without -v
 hg serve -a localhost -p 20063 -d --pid-file=hg.pid
-kill `cat hg.pid`
+cat hg.pid >> "$DAEMON_PIDS"
 
 echo % With -v
-hg serve -a localhost -p 20063 -d --pid-file=hg.pid -v
-kill `cat hg.pid`
+hg serve -a localhost -p 20064 -d --pid-file=hg.pid -v
+cat hg.pid >> "$DAEMON_PIDS"

tests/test-serve.out

@@ -1,3 +1,3 b''
 % Without -v
 % With -v
-listening at http://localhost:20063/
+listening at http://localhost:20064/