Fix regression caused by pull #9629

Regression tests caught the following:

http://jenkins.saltstack.com/job/salt-rs-debian7/1368/testReport/integration.modules.file/FileModuleTest/test_source_list_for_list_returns_file_from_dict/

This commit fixes the regression.
Merge pull request #9641 from terminalmage/issue9620

Fix regression caused by pull #9629