Fix noisy Reform accessor deprecation warnings

    [Reform] Deprecation WARNING: When using Composition, you may not call Form#query anymore to access the contained model. Please use Form#model[:query] and have a lovely day!

See https://github.com/apotonick/reform/blob/master/CHANGES.md#101

Signed-off-by: Alex Coles <alex@alexbcoles.com>
Merge pull request #1531 from opf/fix/api-reform-deprecation-warnings

Fix noisy Reform model accessor deprecation warnings