fix typos in verbose message command

[franknarf1]

With current code, I got a malformed message like...

i. e_id has same type ( character ) as x. e_id . No coercion needed.i. rank has same type ( integer ) as x. rank . No coercion needed.Calculated ad hoc index in 0.010s elapsed (0.000s cpu)

That is: spaces where there shouldn't be any and no newlines between columns in the loop.

Off-topic: I reviewed the Contributing guidelines, but still have more to learn about PRs, testing etc (... planning to in a couple months). I'm making this edit through the github website, since I figure that's simpler than opening a new issue, but am not running test.data.table() etc.

[MichaelChirico]

LGTM, just monitor tests to see if any were depending on that output format

[codecov]

Codecov Report

Merging #3710 into master will not change coverage.
The diff coverage is 100%.

@@          Coverage Diff           @@
##           master   #3710   +/-   ##
======================================
  Coverage    98.3%   98.3%           
======================================
  Files          69      69           
  Lines       13267   13267           
======================================
  Hits        13042   13042           
  Misses        225     225

Impacted Files	Coverage Δ
R/bmerge.R	100% <100%> (ø)	⬆️

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[MichaelChirico]

still have more to learn about PRs, testing etc (... planning to in a couple months)

re:this, I've been thinking it would be helpful to have something like "Your first PR" that does a walk-through of all the steps of the process. It might be helpful if you could make note of your pain points (even on things completely unrelated to data.table per se such as issues with command-line git)

[mattdowle]

Yes: LGTMT. Looking forward to your PRs @franknarf1!
There's the Minimal-first-time-PR section here :
https://github.com/Rdatatable/data.table/wiki/Contributing#minimal-first-time-pr