pgsql: Minor editorial improvements in documentation of - Mailing list pgsql-committers

Log Message:
-----------
Minor editorial improvements in documentation of session_replication_role;
in particular correct the obsolete claim that it can't be changed once
any plans have been cached.

Modified Files:
--------------
    pgsql/doc/src/sgml:
        config.sgml (r1.161 -> r1.162)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/config.sgml?r1=1.161&r2=1.162)
    pgsql/src/backend/utils/misc:
        guc.c (r1.430 -> r1.431)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/misc/guc.c?r1=1.430&r2=1.431)
        postgresql.conf.sample (r1.234 -> r1.235)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/misc/postgresql.conf.sample?r1=1.234&r2=1.235)