Freestyle: Fix for dashed lines when applied to invisible stroke segments.

Dashed lines were resetting stroke segment visibility by mistake (making invisible segments
visible, for example when applied to the results of square blueprint geometry modifier).

release/scripts/freestyle/modules/parameter_editor.py

@@ -955,7 +955,8 @@ class DashedLineShader(StrokeShader):
                 if index == len(self._pattern):
                     index = 0
                 visible = not visible
-            it.object.attribute.visible = visible
+            if not visible:
+                it.object.attribute.visible = visible
             it.increment()