[nat] Remove range checks inside the VTY command.

The ranges are enforced by the VTY code.
diff --git a/openbsc/src/nat/bsc_nat_vty.c b/openbsc/src/nat/bsc_nat_vty.c
index 79b7849..696a47c 100644
--- a/openbsc/src/nat/bsc_nat_vty.c
+++ b/openbsc/src/nat/bsc_nat_vty.c
@@ -346,12 +346,6 @@
 
 	int lac = atoi(argv[0]);
 
-	if (lac < 0 || lac > 0xffff) {
-		vty_out(vty, "%% LAC %d is not in the valid range (0-65535)%s",
-			lac, VTY_NEWLINE);
-		return CMD_WARNING;
-	}
-
 	if (lac == GSM_LAC_RESERVED_DETACHED || lac == GSM_LAC_RESERVED_ALL_BTS) {
 		vty_out(vty, "%% LAC %d is reserved by GSM 04.08%s",
 			lac, VTY_NEWLINE);