fix stale help message

when parsing command-line options, the -f option support disabling
8 scan and join methods, o, b and t disable index-only scans,
bitmap index scans, and TID scans respectively, add them to the
help message.

diff --git a/src/backend/main/main.c b/src/backend/main/main.c
index 5a964a0db6..f5da4260a1 100644
--- a/src/backend/main/main.c
+++ b/src/backend/main/main.c
@@ -351,7 +351,7 @@ help(const char *progname)
        printf(_("  -?, --help         show this help, then exit\n"));

        printf(_("\nDeveloper options:\n"));
-       printf(_("  -f s|i|n|m|h       forbid use of some plan
types\n"));
+       printf(_("  -f s|i|o|b|t|n|m|h forbid use of some plan
types\n"));
        printf(_("  -n                 do not reinitialize shared
memory after abnormal exit\n"));
        printf(_("  -O                 allow system table structure
changes\n"));
        printf(_("  -P                 disable system indexes\n"));

-- 
Regards
Junwang Zhao