wmbiff: Add missing command line options to documentation.

Closes Debian bug #770117 [1].

[1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=770117

wmbiff/wmbiff/wmbiff.1

@@ -87,6 +87,10 @@ be careful and consider alerting your mail system
 administrator first.  The need to use this option is a sign
 of server misconfiguration.
 .TP
+.B \-relax
+Assume the configuration is correct, parse it without paranoia,
+and assume hostnames are okay.
+.TP
 .B \-o
 Enable classical mode look and behaviour: shows the number of
 new mail messages, if any, or the total number of messages.

wmbiff/wmbiff/wmbiff.c

@@ -1249,6 +1249,7 @@ static void usage(void)
 		   "    -relax                    assume the configuration is \n"
 		   "                              correct, parse it without paranoia, \n"
 		   "                              and assume hostnames are okay.\n"
+	           "    -o                        enable classical mode look and behaviour\n"
 		   "    -v                        print the version number\n"
 		   "    +w                        not withdrawn: run as a window\n"
 		   "\n", PACKAGE_VERSION, PACKAGE_BUGREPORT);