Position control - noPositionText with empty value show false

[asemoller]

Describe the bug
If "noPositionText" has an empty value, the text "false" is displayed in the footer.

To Reproduce
Steps to reproduce the behavior:

1. Add the position control
2. Set "noPositionText" to ""
3. Move the mouse over the map and then move it off the map
4. See error

Expected behavior
The last mouse position should be rendered.

Screenshots

Desktop (please complete the following information):

• OS: windows
• Browser: chrome

[steff-o]

I can confirm that this is a bug introduced in #1648 when OpenLayers changed the interpretation of the placeholder parameter in the MousePosition class to only show last known coordinate when the placeholder is undefined.

Currently there is no way of configuring a workaround as an omitted parameter is in code replaced with a non breaking space.