"quarkus.http.test-timeout" Was removed ? (using 1.12.1.Final)
I have this in my application.properties
# timeout for junit RestAssured / debug
%test.quarkus.http.test-timeout=600s

I'm using : <quarkus.platform.version>1.12.1.Final</quarkus.platform.version>

and now I obtain this in the logs 
2021-03-18 12:47:35,512 WARN  [io.qua.config] (main) Unrecognized configuration key "quarkus.http.test-timeout" was provided; it will be ignored; verify that the dependency extension for this configuration is set or you did not make a typo

In that guide : https://quarkus.io/guides/getting-started-testing
4.2. Controlling HTTP interaction timeout
When using REST Assured in your test, the connection and response timeouts are set to 30 seconds. You can override this setting with the quarkus.http.test-timeout property:

quarkus.http.test-timeout=10s



It should be a false warning: 


diff --git a/extensions/vertx-http/runtime/src/main/java/io/quarkus/vertx/http/runtime/HttpBuildTimeConfig.java b/extensions/vertx-http/runtime/src/main/java/io/quarkus/vertx/http/runtime/HttpBuildTimeConfig.java
index 172a24288d0..6bca11e7fe1 100644
--- a/extensions/vertx-http/runtime/src/main/java/io/quarkus/vertx/http/runtime/HttpBuildTimeConfig.java
+++ b/extensions/vertx-http/runtime/src/main/java/io/quarkus/vertx/http/runtime/HttpBuildTimeConfig.java
@@ -1,5 +1,7 @@
 package io.quarkus.vertx.http.runtime;
 
+import java.time.Duration;
+
 import io.quarkus.runtime.annotations.ConfigItem;
 import io.quarkus.runtime.annotations.ConfigPhase;
 import io.quarkus.runtime.annotations.ConfigRoot;
@@ -68,4 +70,10 @@ public class HttpBuildTimeConfig {
      */
     @ConfigItem(defaultValue = "true")
     public boolean redirectToNonApplicationRootPath;
+
+    /**
+     * The REST Assured client timeout for testing.
+     */
+    @ConfigItem(defaultValue = "30s")
+    public Duration testTimeout;
 }
['extensions/vertx-http/runtime/src/main/java/io/quarkus/vertx/http/runtime/HttpBuildTimeConfig.java']