Fix NPE in account presence submenu of global status popup menu.

A NPE occurred occasionally when selecting an (arbitrary?) account for
which there was a presence popup menu is available. These popup menus
can be found within the global status popup menu for each of the
available (enabled) accounts.

The cause of the exception turned out to be the titleArea which holds
the account name and optional status message. I'm not sure what exactly
causes the NPE itself, but it might have to do with the size of the edit
pane and size of the content vs. the size of the menu.

The stack trace that would occur if on occasion this NPE would occur:

23:23:10.642 SEVERE: [35] util.UtilActivator.uncaughtException().108 An uncaught exception occurred in thread=Thread[AWT-EventQueue-0,6,main] and message was: null
java.lang.NullPointerException
	at javax.swing.BoxLayout.checkRequests(BoxLayout.java:485)
	at javax.swing.BoxLayout.preferredLayoutSize(BoxLayout.java:300)
	at javax.swing.plaf.basic.DefaultMenuLayout.preferredLayoutSize(DefaultMenuLayout.java:60)
	at java.awt.Container.preferredSize(Container.java:1788)
	at java.awt.Container.getPreferredSize(Container.java:1773)
	at javax.swing.JComponent.getPreferredSize(JComponent.java:1653)
	at java.awt.BorderLayout.preferredLayoutSize(BorderLayout.java:719)
	at java.awt.Container.preferredSize(Container.java:1788)
	at java.awt.Container.getPreferredSize(Container.java:1773)
	at javax.swing.JComponent.getPreferredSize(JComponent.java:1653)
	at javax.swing.JRootPane$RootLayout.preferredLayoutSize(JRootPane.java:917)
	at java.awt.Container.preferredSize(Container.java:1788)
	at java.awt.Container.getPreferredSize(Container.java:1773)
	at javax.swing.JComponent.getPreferredSize(JComponent.java:1653)
	at java.awt.BorderLayout.preferredLayoutSize(BorderLayout.java:719)
	at java.awt.Container.preferredSize(Container.java:1788)
	at java.awt.Container.getPreferredSize(Container.java:1773)
	at java.awt.Window.pack(Window.java:809)
	at javax.swing.Popup$HeavyWeightWindow.show(Popup.java:252)
	at javax.swing.Popup.show(Popup.java:105)
	at javax.swing.JPopupMenu.getPopup(JPopupMenu.java:834)
	at javax.swing.JPopupMenu.setVisible(JPopupMenu.java:783)
	at javax.swing.JPopupMenu.show(JPopupMenu.java:953)
	at javax.swing.JMenu.setPopupMenuVisible(JMenu.java:351)
	at javax.swing.JPopupMenu.menuSelectionChanged(JPopupMenu.java:1465)
	at javax.swing.MenuSelectionManager.setSelectedPath(MenuSelectionManager.java:117)
	at javax.swing.plaf.basic.BasicMenuUI.appendPath(BasicMenuUI.java:222)
	at javax.swing.plaf.basic.BasicMenuUI.access$200(BasicMenuUI.java:49)
	at javax.swing.plaf.basic.BasicMenuUI$Actions.actionPerformed(BasicMenuUI.java:280)
	at javax.swing.Timer.fireActionPerformed(Timer.java:312)
	at javax.swing.Timer$DoPostEvent.run(Timer.java:244)
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:312)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:733)
	at java.awt.EventQueue.access$200(EventQueue.java:103)
	at java.awt.EventQueue$3.run(EventQueue.java:694)
	at java.awt.EventQueue$3.run(EventQueue.java:692)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:703)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)