dlopen-test: Add missing libraries to the check list
    
    nfsidmap plugin(sss.so) and libsss_cert.so were not checked.
    Few libraries which are build for testing purposes were added to the list
    otherwise we would not be able to detect unchecked libraries.
    
    Reviewed-by: Petr Čech <pcech@redhat.com>
    (cherry picked from commit 558b8f3cd2439c01e139cf5f812aea9409fe776a)