Fallback to p-u 3.5.1

Author: cstamas

maven-plugin-testing-harness/pom.xml

@@ -113,18 +113,10 @@ under the License.
       </exclusions>
     </dependency>
 
-    <!-- plexus -->
     <dependency>
       <groupId>org.codehaus.plexus</groupId>
       <artifactId>plexus-utils</artifactId>
-      <version>4.0.1</version>
-    </dependency>
-    <dependency>
-      <!-- correct version must be provided by project depends on Maven version -->
-      <groupId>org.codehaus.plexus</groupId>
-      <artifactId>plexus-xml</artifactId>
-      <version>4.0.3</version>
-      <optional>true</optional>
+      <version>3.5.1</version>
     </dependency>
     <dependency>
       <groupId>org.codehaus.plexus</groupId>