investigate: splash page does not always load

[nanometrenat]

When a user is connected via wifi to a mesh extender (via the servalproject.org mesh extender) the Serval Mesh splash screen, with info about the project and a link to the app, is meant to automatically display.

However we noticed that a number of times - both on laptops using Firefox and on phones - this splash screen does not always load - whether browsing to mesh.extender or to 192.168.3.1

The Radio and wifi diagnostics pages (same IP address, but specified ports) loaded fine though.

In one case there was a known reason (splash screen had been turned off by Paul) however in other cases we could see no explanation - investigation required as to what's going on here.