fixed site publication failure
diff --git a/pom.xml b/pom.xml
index 5f9d845..1485753 100644
--- a/pom.xml
+++ b/pom.xml
@@ -318,6 +318,19 @@
         </plugin>
       </plugins>
     </pluginManagement>
+    <plugins>
+      <plugin><!-- TODO remove when upgrading to parent pom 31 -->
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-enforcer-plugin</artifactId>
+        <dependencies>
+          <dependency>
+            <groupId>org.codehaus.mojo</groupId>
+            <artifactId>extra-enforcer-rules</artifactId>
+            <version>1.0-beta-6</version>
+          </dependency>
+        </dependencies>
+      </plugin>
+    </plugins>
   </build>
 
   <profiles>