Minimap camera moves on its own

<Bug>
When you press the arrow keys on the keyboard while the Currency Exchange is open,
the camera position on the minimap moves on its own.

<Repro steps>
1. Press the Tab key several times to display the minimap in the center.
2. Talk to Faustus to open the Currency Exchange.
3. Click the field where you enter the quantity.
4. Press the left and right arrow keys on your keyboard.
5. The minimap camera position moves on its own unexpectedly.

<Expected Behaviour>
Prevent the camera position on the minimap from moving while Currency Exchange is open.