[epub-rs-33] Normative references to discontinued specs in EPUB Reading Systems 3.3

[dontcallmedom-bot]

While crawling EPUB Reading Systems 3.3, the following normative referenced were detected as pointing to discontinued specifications:

• [ ] rfc7230 has been obsoleted by rfc9110,rfc9112

_{This issue was detected and reported semi-automatically by Strudy based on data collected in webref.}

[iherman]

Indeed. It should be replaced by 9110.

[iherman]

Duplicate of #2595; closing.