fix request body parameter template

[keramix]

fixes #1213

[codecov]

Codecov Report

Merging #1230 into master will not change coverage.
The diff coverage is 100%.

@@           Coverage Diff           @@
##           master    #1230   +/-   ##
=======================================
  Coverage   67.52%   67.52%           
=======================================
  Files          28       28           
  Lines        7808     7808           
=======================================
  Hits         5272     5272           
  Misses       2049     2049           
  Partials      487      487

Impacted Files	Coverage Δ
generator/bindata.go	60.32% <100%> (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 188e0cd...ecfb53c. Read the comment docs.