accounts.google.co.uk uses security technology that is outdated and vulnerable to attack. An attacker could easily reveal information which you thought to be safe.
A workaround to fix this ANNOYING issue is;
network.http.spdy.enabled.http2 = false in
about:config
Type about:config<enter> in the address bar.
If a warning screen comes up, press the I Accept the Risk button.
At the top of the screen is a search bar.