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

[noah8713]

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

[noah8713]

@kanaka kindly see if this works. Since the description is long, I did commit thrice as the message description was not aligning proper spaces.

[DirectXMan12]

@kanaka, this look good to you? I'd like to figure out a way to log the messages somehow, but I think for the time being this fix is fine with me. 👍

@noah8713 I'd prefer if you collapsed the commits together, but I can do that myself when I merge.

[noah8713]

@DirectXMan12 sounds good and thanks since you guys have admin access. :)

[jeffforbes]

This may also fix the issue I submittedL
multiprocessing exception: No Child processes #193

[noah8713]

@kanaka @DirectXMan12 : Can you please help for merging the same?

[noah8713]

squashed and merge into a single commit for my change.

[noah8713]

@DirectXMan12 and @kanaka any updates on this? :(

[kanaka]

LGTM

[noah8713]

Sweet. 👍