[MPMD-291] - Upgrade to PMD 6.21.0

Author: adangel

pom.xml

@@ -88,7 +88,7 @@ under the License.
     <mavenVersion>3.0</mavenVersion>
     <doxiaVersion>1.7</doxiaVersion>
     <javaVersion>7</javaVersion><!-- Because PMD 5.4+ requires Java 7 -->
-    <pmdVersion>6.19.0</pmdVersion>
+    <pmdVersion>6.21.0</pmdVersion>
     <sitePluginVersion>3.7.1</sitePluginVersion>
     <projectInfoReportsPluginVersion>3.0.0</projectInfoReportsPluginVersion>
   </properties>

src/site/apt/examples/upgrading-PMD-at-runtime.apt.vm

@@ -88,7 +88,7 @@ Upgrading PMD at Runtime
 *--------------------------------------------------------------------------------*--------------------------------------------------*
 | <<maven-pmd-plugin>>                                                           | <<PMD>>                                          |
 *--------------------------------------------------------------------------------*--------------------------------------------------*
-| {{{https://maven.apache.org/plugins-archives/maven-pmd-plugin-3.13.0/}3.13.0}} | {{{https://pmd.github.io/pmd-6.19.0/}6.19.0}}    |
+| {{{https://maven.apache.org/plugins-archives/maven-pmd-plugin-3.13.0/}3.13.0}} | {{{https://pmd.github.io/pmd-6.21.0/}6.21.0}}    |
 *--------------------------------------------------------------------------------*--------------------------------------------------*
 | {{{https://maven.apache.org/plugins-archives/maven-pmd-plugin-3.12.0/}3.12.0}} | {{{https://pmd.github.io/pmd-6.13.0/}6.13.0}}    |
 *--------------------------------------------------------------------------------*--------------------------------------------------*