sgsn_vty: Fix mmctx rate_ctr output indentation

Change-Id: I1b89c179e1ba08b65e31727fdce90c7b578f4d6d
diff --git a/src/gprs/sgsn_vty.c b/src/gprs/sgsn_vty.c
index 42b5121..0663131 100644
--- a/src/gprs/sgsn_vty.c
+++ b/src/gprs/sgsn_vty.c
@@ -533,7 +533,7 @@
 		pfx, get_value_string(gprs_mm_st_strs, mm->gmm_state),
 		osmo_rai_name(&mm->ra), mm->gb.cell_id, VTY_NEWLINE);
 
-	vty_out_rate_ctr_group(vty, " ", mm->ctrg);
+	vty_out_rate_ctr_group(vty, "  ", mm->ctrg);
 
 	if (pdp) {
 		struct sgsn_pdp_ctx *pdp;