bitbake: uievent: retry on handler registration failure

bitbake: uievent: retry on handler registration failure

The registration of a remote UI event handler may fail
if the server cooker is currently in some certain states.
This may happen, for example, when a remote UI is started
very fast after the bitbake server is started, and the
server hadn't time to finish initial configuration parsing.

Rather than fail outright, we have the remote UI event retry
registration for five time at one-second intervals,
in the hope it will succeed.

(Bitbake rev: c3d520c92ae4ae80d31926a416456df510654b6a)

Signed-off-by: Alexandru DAMIAN <alexandru.damian@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>