Convert some remaining string concatenations to f-strings

[machawk1]

No description provided.

[codecov]

Codecov Report

Merging #722 into master will not change coverage.
The diff coverage is 28.57%.

@@           Coverage Diff           @@
##           master     #722   +/-   ##
=======================================
  Coverage   30.06%   30.06%           
=======================================
  Files          10       10           
  Lines        1264     1264           
  Branches      185      185           
=======================================
  Hits          380      380           
  Misses        861      861           
  Partials       23       23           

Impacted Files	Coverage Δ
ipwb/replay.py	15.90% <0.00%> (ø)
ipwb/indexer.py	50.19% <40.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 649e486...e9dd873. Read the comment docs.

[ibnesayeed]

LGTM!