Bug in adding new tab to debugger

When a new debugger is shown, the implementation of

org.jivesoftware.smackx.debugger.EnhancedDebuggerWindow#showNewDebugger

attempts to add a new tab to a JTabbedPane by counting the components in the tabbed pane, and adding the new tab to 'index minus one'.

The amount of components in a JTabbedPane need not be equal to the amount of tabs in the pane, which can cause

IndexOutOfBoundException

to be thrown.

When adding a new tab 'to the end' of the pane, the index

-1

can (should?) be used as a shortcut to get the correct index.