Bump waitress from 1.4.1 to 1.4.3

[dependabot]

Bumps waitress from 1.4.1 to 1.4.3.

Changelog

Sourced from waitress's changelog.

1.4.3 (2020-02-02)

Security Fixes

- In Waitress version 1.4.2 a new regular expression was added to validate the
  headers that Waitress receives to make sure that it matches RFC7230.
  Unfortunately the regular expression was written in a way that with invalid
  input it leads to catastrophic backtracking which allows for a Denial of
  Service and CPU usage going to a 100%.
This was reported by Fil Zembowicz to the Pylons Project. Please see
GHSA-73m2-3pwg-5fgc
for more information.
1.4.2 (2020-01-02)
Security Fixes

• This is a follow-up to the fix introduced in 1.4.1 to tighten up the way Waitress strips whitespace from header values. This makes sure Waitress won't accidentally treat non-printable characters as whitespace and lead to a potental HTTP request smuggling/splitting security issue.

  Thanks to ZeddYu Lu for the extra test cases.

  Please see the security advisory for more information: GHSA-m5ff-3wj3-8ph4

  CVE-ID: CVE-2019-16789

Bugfixes

- Updated the regex used to validate header-field content to match the errata
  that was published for RFC7230.
See: https://www.rfc-editor.org/errata_search.php?rfc=7230&eid=4189

Commits

• cbc89bf Prep v1.4.3
• 6e46f9e Merge pull request from GHSA-73m2-3pwg-5fgc
• 51b9bd4 Remove accidental backslash
• f87abb7 Add bad header that caused catastrophic backtracking
• 2fe8e54 Add header parsing tests with short headers
• ac0ca05 Remove catastrophic backtracking in regex
• 8af9adb Prep for 1.4.2
• 634d991 Merge pull request #277 from Pylons/invalid-whitespace-cont
• 3a54e29 Add CHANGES and bump version to 1.4.2
• 0bf98da Update RFC7230 regex with errata for header field-content
• Additional commits viewable in compare view

Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting @dependabot rebase.

---

Dependabot commands and options

You can trigger Dependabot actions by commenting on this PR:

• @dependabot rebase will rebase this PR
• @dependabot recreate will recreate this PR, overwriting any edits that have been made to it
• @dependabot merge will merge this PR after your CI passes on it
• @dependabot squash and merge will squash and merge this PR after your CI passes on it
• @dependabot cancel merge will cancel a previously requested merge and block automerging
• @dependabot reopen will reopen this PR if it is closed
• @dependabot close will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually
• @dependabot ignore this major version will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this minor version will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this dependency will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)
• @dependabot use these labels will set the current labels as the default for future PRs for this repo and language
• @dependabot use these reviewers will set the current reviewers as the default for future PRs for this repo and language
• @dependabot use these assignees will set the current assignees as the default for future PRs for this repo and language
• @dependabot use this milestone will set the current milestone as the default for future PRs for this repo and language

You can disable automated security fix PRs for this repo from the Security Alerts page.