Do not compute areas if `min_inters` is 0

Optimization.

Overlap/inters_lines.f90

@@ -33,9 +33,13 @@ contains
        inters_lines = .false.
     else
        ! polyline_1 and polyline_2 overlap
-       inters_lines = spher_polygon_area(res_pol) >= min_inters &
-            * min(abs(spher_polyline_area(polyline_1)), &
-            abs(spher_polyline_area(polyline_2)))
+       if (min_inters > 0.) then
+          inters_lines = spher_polygon_area(res_pol) >= min_inters &
+               * min(abs(spher_polyline_area(polyline_1)), &
+               abs(spher_polyline_area(polyline_2)))
+       else
+          inters_lines = .true.
+       end if
     end if
 
   end function inters_lines