DOCS-7138, DOCS-8576 remove writeConcernMajorityJournalDefault and explicit j since we already state the setting applies if j is unspecified

Author: kay-kim

source/reference/replica-configuration.txt

@@ -121,9 +121,6 @@ Replica Set Configuration Fields
           the voting members have applied the operation in
           memory.
 
-   If :ref:`j <wc-j>` is specified in the write concern, MongoDB uses
-   the :ref:`journal <wc-j>` behavior specified in the write concern.
-   
    .. seealso:: :ref:`wc-ack-behavior`
 
 ``members``