Screens display working time if dynamic graph element is used

Steps to reproduce:

1. Create a graph (or graph prototype) with option Show working time switched off
2. Add the graph (or prototype) to a screen with dynamic option enabled

Result:
The working time is displayed in the background of the graph.

Expected:
The working time is not displayed in the background.

Notes:
If the graph is not set to dynamic, working time is not displayed.
This works properly on the dashboards with dynamic classic graphs, only screens are affected