test-https: kill only hgweb daemon to restart for client-auth test

This avoids a test failure on Mac OS X. Because tinyproxy.py isn't detached
from the shell, it may complain that a child process is terminated by a signal.

tests/test-https.t

@@ -346,7 +346,7 b' Test https with cert problems through pr'
   [255]
 
 
-  $ "$TESTDIR/killdaemons.py" $DAEMON_PIDS
+  $ "$TESTDIR/killdaemons.py" hg0.pid
 
 #if sslcontext