Use random port for wiremock based unit test
diff --git a/src/test/java/org/apache/maven/plugins/pmd/PmdReportTest.java b/src/test/java/org/apache/maven/plugins/pmd/PmdReportTest.java
index b539e79..f1a9b58 100644
--- a/src/test/java/org/apache/maven/plugins/pmd/PmdReportTest.java
+++ b/src/test/java/org/apache/maven/plugins/pmd/PmdReportTest.java
@@ -147,7 +147,7 @@
         PmdReport mojo = (PmdReport) lookupMojo( "pmd", testPom );
 
         // Additional test case for MPMD-174 (https://issues.apache.org/jira/browse/MPMD-174).
-        WireMockServer mockServer = new WireMockServer( 3456 );
+        WireMockServer mockServer = new WireMockServer();
         mockServer.start();
 
         String sonarRuleset =