Fix default port setting reversion

The problem:  begin modifying the server settings by changing the security
type (which will change the port to a default value), then change the port
to a custom value, then change screen orientation.  The default port value
is restored, wiping out the custom value.

When onRestoreInstanceState() is called, the custom port value is
restored.  But the spinner doesn't actually restore its state at that
time.  Instead, it waits until View.layout(), at which time it posts a
runnable to call onItemSelected() if the restored state doesn't match the
state initialized in onCreate().  When onItemSelected() is eventually run
sometime later, it wipes out the custom port value that was restored.

The solution is to keep track of the spinner state ourselves and only
revert the port to a default when we see the spinner state changed by the
user.

This problem goes back to 4.904 and before.