Bug#569905: URL completion bogs down after a few months of browsing, with no way to truncate

[jidanni at jidanni.org]

MH> Even with Edit > Preferences > Privacy > Clear your recent history ?
Thanks for replying.
There is no exact such button there, instead mainly day selectors. However there is
Tools > Clear recent history ...> Everything
But upon restarting firefox, one sees it still remembers some completions.