composable+recolorable cinema database default export has no attribute array images

@demarle @dhr @patchett2002

Tested with master branch.

To recreate:

1. Create a wavelet source, color by RTData, apply
2. Open export inspector, choose cinema database for image extract, check its box, and open the options
3. Change "Deferred Rendering" from "None" to "Composable+Recolorable"
4. File -> Export Now or Catalyst -> Export Now

There is only one zlib compressed float file, which is the composable float file. It is expected to have the same result as Export Scene as cdb in 5.5.2 which does have the two float files.