Bump h2 from 0.3.16 to 0.3.20

Bumps [h2](https://github.com/hyperium/h2) from 0.3.16 to 0.3.20.
- [Release notes](https://github.com/hyperium/h2/releases)
- [Changelog](https://github.com/hyperium/h2/blob/master/CHANGELOG.md)
- [Commits](https://github.com/hyperium/h2/compare/v0.3.16...v0.3.20)

---
updated-dependencies:
- dependency-name: h2
  dependency-type: indirect
  update-type: version-update:semver-patch
...

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

Cargo.lock

@@ -736,9 +736,9 @@ checksum = "d2fabcfbdc87f4758337ca535fb41a6d701b65693ce38287d856d1674551ec9b"
 
 [[package]]
 name = "h2"
-version = "0.3.16"
+version = "0.3.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5be7b54589b581f624f566bf5d8eb2bab1db736c51528720b6bd36b96b55924d"
+checksum = "97ec8491ebaf99c8eaa73058b045fe58073cd6be7f596ac993ced0b0a0c01049"
 dependencies = [
  "bytes",
  "fnv",