Fix configuration access in the reactive messaging dev console widget

[cescoffier]

Fix how is retrieved the configuration (See smallrye/smallrye-reactive-messaging#2235 for details)

Fix smallrye/smallrye-reactive-messaging#2235.

[quarkus-bot]

Failing Jobs - Building 74f159a

Status	Name	Step	Failures	Logs	Raw logs
✔️	JVM Tests - JDK 11
✔️	JVM Tests - JDK 17
✖	JVM Tests - JDK 17 Windows	Build	Failures	Logs	Raw logs
✔️	JVM Tests - JDK 20

Full information is available in the Build summary check run.

Failures

⚙️ JVM Tests - JDK 17 Windows #

- Failing: integration-tests/rest-client 

📦 integration-tests/rest-client

✖ io.quarkus.it.rest.client.selfsigned.ExternalSelfSignedTestCase.should_accept_self_signed_certs_java_url line 27 - More details - Source on GitHub

java.net.SocketTimeoutException: Read timed out
	at java.base/sun.nio.ch.NioSocketImpl.timedRead(NioSocketImpl.java:288)
	at java.base/sun.nio.ch.NioSocketImpl.implRead(NioSocketImpl.java:314)