Don't limit dialog height of Account Creation Wizard (Captcha hidden)

problem

Current Account Creation Wizard makes bad impression.

analysis

For example, when server prompts user to use anti-spam measures, a scroll-bar may appear, due to CAPTCHA image ans URL field to that image, since this dialog is fixed - this appearance is ugly.

enhancement recommendation

Use the same wizard dialog used for Ad-hoc Commands.

Related to #7512 (closed).