gors_ns2_vty: Fix saving of new NS2 timers

In I00e9023a6e7adc6ad48f4016fcaef189ac8b353e we introduced
two new timers, but failed to add the related value_string[]
entries.  This caused the VTY code to save something like

 timer unknown 0x8 3
 timer unknown 0x9 3

which fails to parse on re-start.

Change-Id: If5cfdf1ef68d98933985406d0ac071a0a1185646
diff --git a/src/gb/gprs_ns2_vty.c b/src/gb/gprs_ns2_vty.c
index 87284c2..742f181 100644
--- a/src/gb/gprs_ns2_vty.c
+++ b/src/gb/gprs_ns2_vty.c
@@ -103,6 +103,8 @@
 	{ 5, "tns-alive" },
 	{ 6, "tns-alive-retries" },
 	{ 7, "tsns-prov" },
+	{ 8, "tsns-size-retries" },
+	{ 9, "tsns-config-retries" },
 	{ 0, NULL }
 };