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

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

https://github.com/couchbase/couchbase-lite-android/issues/398
stub out testGetReplicator()

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