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/gtphub_main.c b/src/gprs/gtphub_main.c
index 585a3cb..6d470bd 100644
--- a/src/gprs/gtphub_main.c
+++ b/src/gprs/gtphub_main.c
@@ -238,7 +238,7 @@
 	printf("  -e,--log-level <nr>      Set a global log level.\n");
 	printf("  -r,--restart-file <path> File for counting restarts [%s].\n",
 	       ccfg->restart_counter_file);
-	printf("  -V,--version         Print the version number.\n");
+	printf("  -V,--version         Print the version.\n");
 }
 
 static void list_categories(void)