net_smtp upgrade to 1.10.0

[MegaphoneJon]

Overview

A library upgrade that should have no effect.

Before

net_smtp 1.9.2.

After

net_smtp 1.10.0

Comments

It's been a thorn in my side for the past 10 years or so that CiviCRM doesn't support STARTTLS on unauthenticated connections.

Some work has been done to fix this upstream, and net_smtp has a new version. They're only 4 commits apart, and the new starttls() function is the only change to code (other commits are documentation, CI change, and tagging a new release).

This isn't enough by itself - we also need a new version of pear/Mail (once this commit is merged). But I'm submitting this because it's a small change that's easily reviewed.

[civibot]

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[seamuslee001]

Library changes seem fine to me merge on pass