ssh-key: please backport the the RSA p/p -> p/q fix to 0.6.x.

[alexzorin]

Hello!

Thank you for your work.

ssh-key has a correctness issue for RSA keys that was fixed like a year and a half ago and never published to a release: 3b41fd9

I can see that the 0.7.0 tag contains this fix, but anybody using cargo add is going to hit this, because it does not naturally pick the pre-release tags.