Revert "Update html5ever"

This reverts commit a3d77ad.

Author: jyn514

Cargo.lock

@@ -25,7 +25,7 @@ badge = { version = "0", path = "src/web/badge" }
 failure = "0.1.3"
 comrak = { version = "0.3", default-features = false }
 toml = "0.5"
-html5ever = "0.24"
+html5ever = "0.22"
 schemamama = "0.3"
 schemamama_postgres = "0.2"
 rusoto_s3 = "0.40"