fix: perhaps MISSING

[shengwudiyi]

fix for unexpected placeholders due to escaping

sample:

msg := `values=%7B%22g`
err := errors.BadRequest("x-reason", msg)

fmt.Println(err.Message == msg) // false
fmt.Println(err.Message)        // values=%!B(MISSING)%!g(MISSING)

[codecov-commenter]

Codecov Report

Merging #1779 (25e43a8) into main (f050b07) will decrease coverage by 0.05%.
The diff coverage is 100.00%.

❗ Current head 25e43a8 differs from pull request most recent head 5c0afc4. Consider uploading reports for the commit 5c0afc4 to get more accurate results

@@            Coverage Diff             @@
##             main    #1779      +/-   ##
==========================================
- Coverage   80.79%   80.74%   -0.06%     
==========================================
  Files          80       80              
  Lines        3557     3557              
==========================================
- Hits         2874     2872       -2     
- Misses        477      479       +2     
  Partials      206      206              

Impacted Files	Coverage Δ
errors/types.go	100.00% <100.00%> (ø)
internal/context/context.go	97.01% <0.00%> (-2.99%)	⬇️

---

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 f050b07...5c0afc4. Read the comment docs.