OWB-960 also 'proxy' the VARARGS modifier

This is sometimes needed e.g. for EL coercing of vararg methods.
txs to Vojtech Zavrel for the report and the fix hint!


git-svn-id: https://svn.apache.org/repos/asf/openwebbeans/trunk@1598967 13f79535-47bb-0310-9956-ffa450edef68