Bump waitress from 1.4.3 to 2.1.2

Bumps [waitress](https://github.com/Pylons/waitress) from 1.4.3 to 2.1.2.
- [Release notes](https://github.com/Pylons/waitress/releases)
- [Changelog](https://github.com/Pylons/waitress/blob/v2.1.2/CHANGES.txt)
- [Commits](Pylons/waitress@v1.4.3...v2.1.2)

---
updated-dependencies:
- dependency-name: waitress
  dependency-type: direct:production
...

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

Author: dependabot[bot]

requirements.txt

@@ -27,7 +27,7 @@ translationstring==1.3
 Unidecode==1.1.1
 urllib3==1.25.9
 venusian==3.0.0
-waitress==1.4.3
+waitress==2.1.2
 WebOb==1.8.6
 zope.deprecation==4.4.0
 zope.interface==5.1.0