v1.9.0

What's Changed

• Version Pro Proofs on the outside instead of the inside by @jagerman in #130
• Fix spurious seqno increment when a merge adopts an incoming config by @jagerman in #132
• quic: actually apply disable_mtu_discovery when the config asks for it by @mpretty-cyro in #133
• attachments: validate file encryption inputs by @Ap4sh in #129
• tests: pin that a valueless d= is not the stream-encryption fragment by @mpretty-cyro in #136
• Carry the file server port in generated download urls by @mpretty-cyro in #134
• Treat the file server pubkey as Ed25519, as Android and Desktop do by @mpretty-cyro in #135
• fix: point the Pro access-not-found url at getsession.org/pro-recover by @Bilb in #137

Full Changelog: v1.8.0...v1.9.0