Add/fix help string for version option

osmo-sgsn was missing the help text of the -V option
gb_proxy still thought of itself as OpenBSC
Omit the name of the program in the help text to avoid such issues in
the future.

Related: OS#1720
Change-Id: Ib57694b6bff7c98a269dc4b4dbb7173349a57b81
diff --git a/src/gprs/sgsn_main.c b/src/gprs/sgsn_main.c
index f12270d..3543517 100644
--- a/src/gprs/sgsn_main.c
+++ b/src/gprs/sgsn_main.c
@@ -209,6 +209,7 @@
 {
 	printf("Some useful help...\n");
 	printf("  -h --help\tthis text\n");
+	printf("  -V --version\tPrint the version\n");
 	printf("  -D --daemonize\tFork the process into a background daemon\n");
 	printf("  -d option --debug\tenable Debugging\n");
 	printf("  -s --disable-color\n");