This PR adds the wxRB_SINGLE style to the wxRadioButton created by the StaticRadioBtnBoxSizer. The reason for this change is that wxGTK doesn't allow a radio button to be unchecked unless it's part of a group containing 2 or more buttons. If it is marked as wxRB_SINGLE then wxWidgets 3.3 will create a hidden button that becomes part of a group making it possible to deselect the button.
This PR adds the
wxRB_SINGLEstyle to thewxRadioButtoncreated by theStaticRadioBtnBoxSizer. The reason for this change is that wxGTK doesn't allow a radio button to be unchecked unless it's part of a group containing 2 or more buttons. If it is marked aswxRB_SINGLEthen wxWidgets 3.3 will create a hidden button that becomes part of a group making it possible to deselect the button.