After removal of GWT UI this feature is not used and this can be
removed.
Create project SSH command is offering a similar --suggest-parents
but this is implemented using a dedicated: SuggestParentCandidates
class.
PolyGerrit UI doesn't offer the list of parent candidates to select
from in create repository dialog.
Change-Id: Iaaa687f4df373bc945632367be49941c939f8b9b