fix default atol (DZERO)

Author: wpbonelli

src/Utilities/MathUtil.f90

@@ -89,7 +89,7 @@ logical function is_close(a, b, rtol, atol, symmetric)
       lrtol = rtol
     end if
     if (.not. present(atol)) then
-      latol = DSAME
+      latol = DZERO
     else
       latol = atol
     end if