vsed: stop collapsing whitespace

[sgn]

MCVE:
printf '%s %s\n' a b >afile
vsed -i -e '/a b/d' afile

Expect:

• afile should be empty
  Actual:
• afile is not empty

General

• This is a new package and it conforms to the quality requirements

Have the results of the proposed changes been tested?

• I use the packages affected by the proposed changes on a regular basis and confirm this PR works for me
• I generally don't use the affected packages but briefly tested this PR