Fix missing icon error in datetime filter template

[dimitri-koenig]

This new datetime filter uses x-datatables.icons.x-circle component, which does not exist. Everywhere else x-icons.x-circle is being used.

[underdpt]

I think I've been hit by this:

Unable to locate a class or view for component [datatables.icons.x-circle].

Any hope this will get merged?

[dotmarn]

I hope this is merged. I usually get the error whenever I try to cache my views. Good job!

[t-raven]

still not merged :(
#587