basic_archive: Fix comments related to NO_INSTALLCHECK
These comments incorrectly referred to shared_preload_libraries as being
required for the test to work.
Thinko in commit
c68a1839902d.
Author: Bharath Rupireddy
Discussion: https://postgr.es/m/CALj2ACXpjFDiXf-L7AARQ4ppuxiDYSKZjyZb=wOa+cgg0zuWAw@mail.gmail.com