419190: ClassCastException when opening query dialog

Call methods on Wizard only if given IWizard is an instance of Wizard,
in other words check type before casting.

Bug: 419190
Change-Id: Ie462e542ecec0d443ab7865d9297e63fa4d9aa93
Task-Url: https://bugs.eclipse.org/bugs/show_bug.cgi?id=419190
3 files changed