[POLICY-81] Modified site-manager pom.xml to prevent superfluous warnings during maven build.

The addition of a <configuration> stub was added to the site-manager
pom.xml. The stub excludes the org.eclipse.persitence:javax.persistence
artifact from the uber-jar created by the maven-shade-plugin.
The artifact was a duplicate and maven was throwing an excessive
amount of warnings.

Change-Id: I1eaeeb569f67aea5578af68d277f44577a20b379
Signed-off-by: Magnusen, Drew (dm741q) <dm741q@att.com>
diff --git a/site-manager/pom.xml b/site-manager/pom.xml
index 8275074..2671a84 100644
--- a/site-manager/pom.xml
+++ b/site-manager/pom.xml
@@ -70,6 +70,13 @@
 						<goals>
 							<goal>shade</goal>
 						</goals>
+						<configuration>
+							<artifactSet>
+								<excludes>
+									<exclude>org.eclipse.persistence:javax.persistence</exclude>
+								</excludes>
+							</artifactSet>
+						</configuration>	
 					</execution>
 				</executions>
 			</plugin>