[V18 + HF2 Geoscape] - Save form and overwrite file

To repro, execute the following steps in geoscape:

1)Save the game -> Works correctly

2)Save the game again -> As file name write the same name as in 1)

3)The Overwrite save warning message is displayed

4)Press esc: the menu is displayed (see the screenshot below)

5)Press esc again: the menu is hidden

6)Press no on the Overwrite save warning

7)The save form does not work any more

I believe that pressing the esc button should not display the main menu when the Overwrite save warning is active.

When the save form is active, pressing esc does nothing.