SpinnerNumberModel causing IllegalArgumentException in some circumstances

The integer spinners in Backups tab in Preferences pane are throwing an exception that prevents a number of preferences tabs from appearing:

java.lang.IllegalArgumentException: (minimum <= value <= maximum) is false
at java.desktop/javax.swing.SpinnerNumberModel.<init>(Unknown Source)
at java.desktop/javax.swing.SpinnerNumberModel.<init>(Unknown Source)
at jalview.jbgui.GPreferences.setIntegerSpinner(GPreferences.java:2571)

This is occurring when a default value is being set to 0 when min=1 and max=6.
Add
if (def < min) def = min