RidingDutchman

I recently started growing a Mirabelle plum tree from seed (seed was collected during our honeymoon, so it has some sentimental value). Its about 2 years old right now. When planting in the ground I made sure to properly expose the root flare, a couple weeks later I noticed it had quite an odd looking S curve, which I didn't spot or pay attention to while planting. It was not yet pot bound at all. Soil is loose and sandy. Is this a sign of a root girdling or other problem? If so, should I dig it back up and try to prune the roots some? I live in the Netherlands, middle of summer at the moment. Would love to hear your suggestions.