Upgrade h2spec-maven-plugin to 1.0.6 (#6616)

Signed-off-by: Olivier Lamy <oliver.lamy@gmail.com>

pom.xml

@@ -981,7 +981,7 @@
         <plugin>
           <groupId>org.mortbay.jetty</groupId>
           <artifactId>h2spec-maven-plugin</artifactId>
-          <version>1.0.5</version>
+          <version>1.0.6</version>
         </plugin>
       </plugins>
     </pluginManagement>

tests/test-distribution/src/test/java/org/eclipse/jetty/tests/distribution/DistributionTests.java

@@ -843,7 +843,7 @@ public class DistributionTests extends AbstractJettyHomeTest
                     // Protocol "h2" must not be enabled because the
                     // http2 Jetty module was not explicitly enabled.
                     assertFalse(run3.getLogs().stream()
-                        .anyMatch(log -> log.contains("h2")));
+                        .anyMatch(log -> log.contains("h2")), "Full logs: " + String.join("", run3.getLogs()));
                 }
             }
         }