Include about.html in org.eclipse.jgit artifact

This is required to enable accessing legal info for
org.eclipse.jgit from
Help > About > Installation Details > Plugins

Change-Id: I73f40dd2018112cd23102954d7647ecdbbbf0d89
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit/pom.xml

@@ -82,6 +82,7 @@
         <directory>.</directory>
         <includes>
           <include>plugin.properties</include>
+          <include>about.html</include>
         </includes>
       </resource>
       <resource>