securedrop-admin: add the expected type of the variable to the description
securedrop-admin: add the expected type of the variable to the description

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