remove missed reference to crypto module
remove missed reference to crypto module

This was still working on current installations because `crypto.pyc` was still
lying around, but was breaking on new installations.

GabeIsman/securedrop,conorsch/securedrop,ageis/securedrop,garrettr/securedrop,ehartsuyker/securedrop,chadmiller/securedrop,ehartsuyker/securedrop,jeann2013/securedrop,jaseg/securedrop,ehartsuyker/securedrop,conorsch/securedrop,jrosco/securedrop,kelcecil/securedrop,harlo/securedrop,harlo/securedrop,pwplus/securedrop,pwplus/securedrop,ehartsuyker/securedrop,kelcecil/securedrop,chadmiller/securedrop,micahflee/securedrop,ehartsuyker/securedrop,jeann2013/securedrop,harlo/securedrop,jaseg/securedrop,heartsucker/securedrop,jaseg/securedrop,GabeIsman/securedrop,micahflee/securedrop,heartsucker/securedrop,jrosco/securedrop,jrosco/securedrop,heartsucker/securedrop,jrosco/securedrop,ageis/securedrop,ageis/securedrop,ageis/securedrop,jeann2013/securedrop,GabeIsman/securedrop,jaseg/securedrop,garrettr/securedrop,GabeIsman/securedrop,pwplus/securedrop,jaseg/securedrop,harlo/securedrop,kelcecil/securedrop,garrettr/securedrop,jeann2013/securedrop,heartsucker/securedrop,conorsch/securedrop,kelcecil/securedrop,micahflee/securedrop,chadmiller/securedrop,harlo/securedrop,garrettr/securedrop,ehartsuyker/securedrop,heartsucker/securedrop,conorsch/securedrop,kelcecil/securedrop,pwplus/securedrop,chadmiller/securedrop,GabeIsman/securedrop,jeann2013/securedrop,harlo/securedrop,jrosco/securedrop,micahflee/securedrop,conorsch/securedrop,chadmiller/securedrop,jeann2013/securedrop,jaseg/securedrop,chadmiller/securedrop,pwplus/securedrop,kelcecil/securedrop,GabeIsman/securedrop,pwplus/securedrop,jrosco/securedrop