Align test_submit_sanitizes_filename unit test to latest development
Align test_submit_sanitizes_filename unit test to latest development

conorsch/securedrop,heartsucker/securedrop,conorsch/securedrop,heartsucker/securedrop,conorsch/securedrop,ehartsuyker/securedrop,heartsucker/securedrop,ehartsuyker/securedrop,ehartsuyker/securedrop,heartsucker/securedrop,conorsch/securedrop,ehartsuyker/securedrop,ehartsuyker/securedrop,heartsucker/securedrop,conorsch/securedrop,ehartsuyker/securedrop