Disable HTTP/2 clear text when quarkus.http.http2 is false

[MikeEdgar]

Disable HTTP/2 clear text when quarkus.http.http2 is false. Currently, H2C remains enabled even when HTTP/2 with TLS is disabled using this property.

Fixes #49592

[quarkus-bot]

Status for workflow Quarkus CI

This is the status report for running Quarkus CI on commit f66af2e.

✅ The latest workflow run for the pull request has completed successfully.

It should be safe to merge provided you have a look at the other checks in the summary.

You can consult the Develocity build scans.

---

Flaky tests - Develocity

⚙️ JVM Tests - JDK 17

📦 extensions/smallrye-reactive-messaging/deployment

❌ io.quarkus.smallrye.reactivemessaging.hotreload.ConnectorChangeTest.testUpdatingConnector - History

• Expecting actual: ["-6","-7","-8","-10","-11","-12","-13","-14"] to start with: ["-6", "-7", "-8", "-9"] - java.lang.AssertionError

java.lang.AssertionError: 

Expecting actual:
  ["-6","-7","-8","-10","-11","-12","-13","-14"]
to start with:
  ["-6", "-7", "-8", "-9"]

	at io.quarkus.smallrye.reactivemessaging.hotreload.ConnectorChangeTest.testUpdatingConnector(ConnectorChangeTest.java:41)

---

⚙️ Gradle Tests - JDK 17 Windows

📦 integration-tests/gradle

❌ io.quarkus.gradle.BuildConfigurationTest.buildNoOverride - History

• Multiple Failures (1 failure) -- failure 1 -- [sub project 'without-configuration', package type 'fast-jar'] Expecting path: - org.assertj.core.error.AssertJMultipleFailuresError

org.assertj.core.error.AssertJMultipleFailuresError: 

Multiple Failures (1 failure)
-- failure 1 --
[sub project 'without-configuration', package type 'fast-jar'] 
Expecting path:
  D:\a\quarkus\quarkus\integration-tests\gradle\target\classes\build-configuration\without-configuration\build\quarkus-app\quarkus-run.jar
to exist (symbolic links were followed).

[cescoffier]

Thanks!

[cescoffier]

For H2C we may need to intercept the request and reject the HTTP/2 ones altogether.