build(deps): bump ddtrace from 1.3.4 to 1.4.2 in /mpcontribs-api

Bumps [ddtrace](https://github.com/DataDog/dd-trace-py) from 1.3.4 to 1.4.2.
- [Release notes](https://github.com/DataDog/dd-trace-py/releases)
- [Changelog](https://github.com/DataDog/dd-trace-py/blob/1.x/CHANGELOG.md)
- [Commits](DataDog/dd-trace-py@v1.3.4...v1.4.2)

---
updated-dependencies:
- dependency-name: ddtrace
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

mpcontribs-api/requirements.txt

@@ -4,7 +4,7 @@ blinker==1.5
 boltons==21.0.0
 css-html-js-minify==2.5.5
 dateparser==1.1.1
-ddtrace==1.3.4
+ddtrace==1.4.2
 dnspython==2.2.1
 filetype==1.1.0
 flasgger @ git+https://github.com/flasgger/flasgger#egg=flasgger-0.9.5