Fixing Listbox hard-coded border width - fixes theming issues.
Fixing Listbox hard-coded border width - fixes theming issues.

As with the ComboBox before, the ListBox hard-coded a 2px border,
instead of querying the fpgStyle for the theme's border widths.

wkitty42/fpGUI,wkitty42/fpGUI,wkitty42/fpGUI,wkitty42/fpGUI,wkitty42/fpGUI,wkitty42/fpGUI