Automated checkin: version bump for fennec 21.0b7 release. DONTBUILD CLOSED TREE a=release

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branch : MOBILE210b7_2013050618_RELBRANCH
Added FENNEC_21_0b7_RELEASE FENNEC_21_0b7_BUILD1 tag(s) for changeset 722e859fb8c1. DONTBUILD CLOSED TREE a=release

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branch : MOBILE210b7_2013050618_RELBRANCH