Time out on the web UI during the 2.4 to 2.5 update

[Stefal]

Describe the bug
With some Gnss station, the upgrade to v2.5.0 could be very slow, and the web app stop.

Expected behavior
The Web UI should wait until the upgrade is terminated

Additional context
During this upgrade the new packet downloads with apt-get could be very slow (I don't know why).
Perhaps we should raise up the timeout in

rtkbase/web_app/static/settings.js

Line 487 in 12c49b1

update_countdown(600, 0);