Upgrade: Bump httpx from 0.18.1 to 0.18.2 (#152)

Bumps [httpx](https://github.com/encode/httpx) from 0.18.1 to 0.18.2.
- [Release notes](https://github.com/encode/httpx/releases)
- [Changelog](https://github.com/encode/httpx/blob/master/CHANGELOG.md)
- [Commits](encode/httpx@0.18.1...0.18.2)

---
updated-dependencies:
- dependency-name: httpx
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements.txt

@@ -9,7 +9,7 @@ gitdb==4.0.7
 GitPython==3.1.18
 h11==0.12.0
 httpcore==0.13.3
-httpx==0.18.1
+httpx==0.18.2
 idna==3.2
 multidict==5.1.0
 openttd-helpers==1.0.1