create_new_profile(): check if abstractions exist
... instead of blindly adding them to the profile, and later crash (and/or cause parser errors) because they don't exist.
References: https://bugzilla.opensuse.org/show_bug.cgi?id=1178527#c1 
I propose this patch for 3.0 and master.
(Older releases would need a different patch because they don't use IncludeRule, and I doubt that "abstractions/base doesn't exist" is a real-world usecase and worth the effort to rewrite this patch for the previous include rule handling.)