Remove additional signal calls in websockify that causes novnc to hang.

Openstack nova novnc-proxy services uses websockify to provide support
for nova vms using novnc proxy. At present, novnc hangs every couple of
weeks. It only resumes post restart of the novnc-proxy which is not
good. Hence, this code in websockify is updated to get rid of additional
signal calls to avoid novnc going in hang state even though process is
running. Basically, we are getting rid of existing msg and vmsg calls in
the websocket.py. This is kind of quick fix but we will need an
additional way of figuring out the logging to make it easy to trace in
case of any further failures in future.

closes bug: novnc/noVNC#556

websockify/websocket.py

@@ -895,11 +895,14 @@ def terminate(self):
         raise self.Terminate()
 
     def multiprocessing_SIGCHLD(self, sig, stack):
-        self.vmsg('Reaping zombies, active child count is %s', len(multiprocessing.active_children()))
+        # TODO: figure out a way to actually log this information without
+        #       calling `log` in the signal handlers
+        multiprocessing.active_children()
 
     def fallback_SIGCHLD(self, sig, stack):
         # Reap zombies when using os.fork() (python 2.4)
-        self.vmsg("Got SIGCHLD, reaping zombies")
+        # TODO: figure out a way to actually log this information without
+        #       calling `log` in the signal handlers
         try:
             result = os.waitpid(-1, os.WNOHANG)
             while result[0]:
@@ -909,11 +912,13 @@ def fallback_SIGCHLD(self, sig, stack):
             pass
 
     def do_SIGINT(self, sig, stack):
-        self.msg("Got SIGINT, exiting")
+        # TODO: figure out a way to actually log this information without
+        #       calling `log` in the signal handlers
         self.terminate()
 
     def do_SIGTERM(self, sig, stack):
-        self.msg("Got SIGTERM, exiting")
+        # TODO: figure out a way to actually log this information without
+        #       calling `log` in the signal handlers
         self.terminate()
 
     def top_new_client(self, startsock, address):