Skip conflicting submissions when creating a group

Skip conflicting submissions when creating a group

It's hard for users to create the group with many submissions as
every time conflict is found group creation fails and they have
to start grouping again, removing conflicting submission.

This change makes repa to skip conflicting submission and continue
group creation without it. It should simplify and spead up RE work a lot.

Change-Id: I5a08059849e63e7fb8a07e4b05f9c81846d8af57
Signed-off-by: Ed Bartosh <eduard.bartosh@intel.com>