If you remove all the constraints and then put them back in. It should work. This happens sometimes when you place your constraints, then move the view by dragging on it by mistake. It has happened to me before. Click on your view and down at the bottom of the storyboard you have a couple of boxes. One of them was for placing your constraints, the one next (to the right) to that has an option to remove all constrain on the view. As long as the view is selected you will remove them all on just the view. Then put them back in the way you want and the warning will go away. You may have just nudged the view a bit without knowing. Let us know if this works.
EDIT #1
That is pretty strange. I have followed my directions in a sample project and things worked out fine. No warnings. However, I noticed that your lower constraint you said was 0. Look at my picture it is actually 88.
I think you need to choose bottom layout guide when you select the lower constraint. I don't know why yours would come out as zero. Give it a go and let us know.