pgsql: Remove tabs from SGML reference files, so their addition can be

Log Message:
-----------
Remove tabs from SGML reference files, so their addition can be detected
in the future.

Modified Files:
--------------
    pgsql/doc/src/sgml/ref:
        clusterdb.sgml (r1.19 -> r1.20)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/clusterdb.sgml.diff?r1=1.19&r2=1.20)
        dropdb.sgml (r1.29 -> r1.30)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/dropdb.sgml.diff?r1=1.29&r2=1.30)
        droplang.sgml (r1.28 -> r1.29)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/droplang.sgml.diff?r1=1.28&r2=1.29)
        initdb.sgml (r1.41 -> r1.42)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/initdb.sgml.diff?r1=1.41&r2=1.42)
        pg_ctl-ref.sgml (r1.39 -> r1.40)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/pg_ctl-ref.sgml.diff?r1=1.39&r2=1.40)
        pg_dumpall.sgml (r1.66 -> r1.67)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/pg_dumpall.sgml.diff?r1=1.66&r2=1.67)
        psql-ref.sgml (r1.184 -> r1.185)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/psql-ref.sgml.diff?r1=1.184&r2=1.185)
        reindexdb.sgml (r1.3 -> r1.4)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/reindexdb.sgml.diff?r1=1.3&r2=1.4)