NITB: remove 'help' output about '-a' option that is removed for ages

This option was present in very early versions of the NITB, but
at least since 2011 it is no longer supported.  It's still listed
in --help output, which is wrong.

Change-Id: I1d2cceb588ec5fb34ec5e2c05a7d8c93310bee88
diff --git a/src/osmo-msc/msc_main.c b/src/osmo-msc/msc_main.c
index 4166159..6c62db3 100644
--- a/src/osmo-msc/msc_main.c
+++ b/src/osmo-msc/msc_main.c
@@ -140,7 +140,6 @@
 	printf("  -c --config-file filename  The config file to use.\n");
 	printf("  -s --disable-color\n");
 	printf("  -l --database db-name      The database to use.\n");
-	printf("  -a --authorize-everyone    Authorize every new subscriber. Dangerous!\n");
 	printf("  -T --timestamp             Prefix every log line with a timestamp.\n");
 	printf("  -V --version               Print the version of OpenBSC.\n");
 	printf("  -P --rtp-proxy             Enable the RTP Proxy code inside OpenBSC.\n");
@@ -163,7 +162,6 @@
 			{"config-file", 1, 0, 'c'},
 			{"disable-color", 0, 0, 's'},
 			{"database", 1, 0, 'l'},
-			{"authorize-everyone", 0, 0, 'a'},
 			{"pcap", 1, 0, 'p'},
 			{"timestamp", 0, 0, 'T'},
 			{"version", 0, 0, 'V' },