Set plugin name to ‘github’

It seems that from Gerrit master it is mandatory
to define the Gerrit-PluginName from JAR manifest
otherwise unexpected behaviours may appear.

Change-Id: I3024b7b9d01a03c91726ab1a49ca6ec6d79c1e4f

github-plugin/pom.xml

diff --git a/github-plugin/pom.xml b/github-plugin/pom.xml
index d6a84ef..8838432 100644
--- a/github-plugin/pom.xml
+++ b/github-plugin/pom.xml
@@ -72,6 +72,7 @@
 
                 <Gerrit-ApiType>${Gerrit-ApiType}</Gerrit-ApiType>
                 <Gerrit-ApiVersion>${Gerrit-ApiVersion}</Gerrit-ApiVersion>
+                <Gerrit-PluginName>github</Gerrit-PluginName>
               </manifestEntries>
             </transformer>
           </transformers>