[MNG-4645] Fix IT to not use the newly supported syntax (#266)

its/core-it-suite/src/test/java/org/apache/maven/it/MavenITmng3748BadSettingsXmlTest.java

@@ -69,7 +69,7 @@ public class MavenITmng3748BadSettingsXmlTest extends AbstractMavenIntegrationTe
             List<String> lines = verifier.loadLines(verifier.getLogFileName(), null);
             boolean foundWarning = false;
             for (String line : lines) {
-                if (line.matches("(?i)\\[WARNING\\].*unrecognised tag.+repositories.+2.*")) {
+                if (line.matches("(?i)\\[WARNING\\].*unrecognised tag.+unknown.+2.*")) {
                     foundWarning = true;
                     break;
                 }

its/core-it-suite/src/test/resources/mng-3748/settings.xml

@@ -1,5 +1,5 @@
 <settings>
-    <repositories>
+    <unknown>
         <repository>
             <id>central</id>
             <url>http://central</url>
@@ -10,5 +10,5 @@
                 <enabled>true</enabled>
             </snapshots>
         </repository>
-    </repositories>
+    </unknown>
 </settings>