fix batcher bug introduced in recent commit.  now all tests pass.

https://github.com/couchbase/couchbase-lite-android/issues/398
testRunReplicationWithError() passes

https://github.com/couchbase/couchbase-lite-android/issues/398
testBuildRelativeURLString() passes

https://github.com/couchbase/couchbase-lite-android/issues/398
testChannels() passes

https://github.com/couchbase/couchbase-lite-android/issues/398