Fix: Unable pick select first point/curve in Curves

Because of an off-by-one error, it was not possible
to select the fist point or curve using the pick_select
operator in the Curves object.

source/blender/editors/curves/intern/curves_selection.cc

@@ -507,7 +507,7 @@ static bool find_closest_curve_to_screen_co(const Depsgraph &depsgraph,
         return b;
       });
 
-  if (closest_data.index > 0) {
+  if (closest_data.index >= 0) {
     return true;
   }