[AAI] Simplify cert retrieval script

As retrieving values is now done via a generic script, let's clean a
little bit cert retrieval in order to be faster.

Issue-ID: OOM-2688
Signed-off-by: Sylvain Desbureaux <sylvain.desbureaux@orange.com>
Change-Id: I98dc2add27f39f615f34b319ea88edeeac987334
5 files changed