This would be considered a Recharacterization of your 2017 IRA Contribution from Traditional to Roth. A Recharacterization is basically a method for you to change your mind about the type of your current year IRA contribution. This Recharacterization does not affect your ability to make your 2018 IRA Contribution so you can still go ahead and make your 2018 IRA Contribution.
Check out this TurboTax FAQ for more details on the difference between Recharacterization and Conversion:
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