This verse strikes me as the only unnecessary verse I've encountered so far in the Havamal. Do we really need to be told not to get up in the night? I don't know, maybe I'm missing something.
There are some other verses that mention that night-time is for sleeping: 23 which reminds us that staying awake at night worrying isn't good; 58 and 59 remind us that night is for sleeping and day is for working; 113 advises us not to sleep in the arms of a woman skilled in magic (magic includes vartious skills including what modern people would call psychological tricks).
Ráðumk þér Loddfáfnir
en þú ráð nemir
njóta mundu ef þú nemr
þér munu góð ef þú getr
nótt þú rísat
nema á njósn sér
eða þú leitir þér innan út staðar
I advise you, Loddfafnir,
to take advice;
you would benefit, it you took it,
good will come to you, if you accept it:
don't get up at night,
unless you are on guard
or are seeking a place outside for yourself.