Update to dockerio.import_image()

Import image was failing for me because the _parse_image_multilogs_string() function was returning a list containing:

[u'\n', u'\r', {'status', '....'}]

The import_image function then takes this returned list and attempts to access the dictionary containing the status by checking index 0 of the list.  Since the status is in index 2, this fails.

This change should prevent '\r' and '\n' from being added to the list.
Merge pull request #15287 from megaclite/patch-1

Update to dockerio.import_image()