* caddytls: require a trust pool for client cert verification modes
Reject verify_if_given and require_and_verify without a trust pool so they stop falling back to system roots.
* Apply suggestion from @francislavoie
Signed-off-by: Francis Lavoie <lavofr@gmail.com>
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Signed-off-by: Francis Lavoie <lavofr@gmail.com>
Co-authored-by: Francis Lavoie <lavofr@gmail.com>