l2.js reads the last index of a reply to know where the next page starts.
With the firmware side of this branch an empty table answers [], and
s[s.length-1] then throws on undefined. It used to answer commas with
nothing between them and throw in JSON.parse instead, so this is the same
case reaching a different line rather than a new one. An empty reply now renders what
has been collected and starts the next pass from zero.
The 4096 entry cap compared the array against the number instead of its
length, so it never fired: an empty array and a 5000 element one both
compare false. Comparing the length restores what the check was for.