bitbake: server/process.py: Change timeout error handling

bitbake: server/process.py: Change timeout error handling

In normal usage, we never hit the timeout issue. If we do, it becomes obvious
that the current error handling is not good enough. The request may have made it
to the server and the answer will get queued. This means the next command may get
the return value from the previous command with suitably puzzling results.

Without rewriting large sections of code, its not possible to avoid this problem.
It is better to increase the timeout to several seconds giving the server a chance
to respond and if it does timeout, hard exit since recovery is not possible with the
code base today.

I'd be happy to see the structure of this code improved but this quick fix at least
stops corrupted builds from happening which has to be a good thing.

(Bitbake rev: 410c11dd10736873f2dc587fbe9119c38831e693)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>