"Send Email to Users" Feature does not respect blocked users

Steps to reproduce

Have a blocked user whom you have email access to.

Navigate to /admin/users

click "Send Email to Users"

Draft Message

Send

Expected behavior

Users who are blocked should not receive the message.

Actual behavior

Blocked users get an email message

Also reported in https://github.com/gogits/gogs/issues/3814

@mattl assigned this to you as issue triage, let me know if that was incorrect.