fix: set proper ttl in createsnapshot

[guangstick]

fix: set proper ttl in createsnapshot

ttl was not added to the expiration time and the Now ts was sent to the server. This leads to errors like "Expire time must be at least 6h from the time the backup was started, which should be XXX, but got XXXX"

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[conventional-commit-lint-gcf]

🤖 I detect that the PR title and the commit message differ and there's only one commit. To use the PR title for the commit history, you can use Github's automerge feature with squashing, or use automerge label. Good luck human!

-- conventional-commit-lint bot
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[guangstick]

@triplequark @igorbernstein2 @telpirion friendly ping mind taking a look at this one-liner PR? Thanks!