Remove unused @javadispatch
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=80416274
Fix an "unused private var" error for a DiagnosticGroup that is registered but never referenced from Java code.
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=80425483