Add missing pmd.xml file to src assembly.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/codec/trunk@1469567 13f79535-47bb-0310-9956-ffa450edef68

Author: garydgregory

src/main/assembly/src.xml

@@ -32,6 +32,7 @@
                 <include>LICENSE-header.txt</include>
                 <include>NOTICE.txt</include>
                 <include>pom.xml</include>
+                <include>pmd.xml</include>
                 <include>RELEASE-NOTES*.txt</include>
                 <include>TODO</include>
             </includes>