Fix parameters used to check if ssh-keygen exists to prevent an indefinite hang.
Fix parameters used to check if ssh-keygen exists to prevent an indefinite hang.

Closes #764

corpsee/php-censor,corpsee/php-censor,php-censor/php-censor,php-censor/php-censor,php-censor/php-censor,corpsee/php-censor