fix bug in sin_task_depends so that only existing paths
fix bug in sin_task_depends so that only existing paths

Signed-off-by: Jordan Wilberding <c75c9afa7ab32355502e631bdcd27e5db15b49c6@gmail.com>

erlware-deprecated/sinan,erlware-deprecated/sinan,ericbmerritt/sinan,erlware-deprecated/sinan,ericbmerritt/sinan,ericbmerritt/sinan