nat: Test for a bug inside the TLV definition for GSM 08.08

The 0x1 inside a CIC IE could indicate a new IE... add test data
and test case to verify that the patching works correctly.
diff --git a/openbsc/tests/bsc-nat/bsc_data.c b/openbsc/tests/bsc-nat/bsc_data.c
index 1bc15c8..f4dba0a 100644
--- a/openbsc/tests/bsc-nat/bsc_data.c
+++ b/openbsc/tests/bsc-nat/bsc_data.c
@@ -86,7 +86,7 @@
 0x00, 0x12, 0xfd, 0x06,
 0x00, 0x00, 0x49, 0x00, 0x01, 0x0b, 0x00, 0x09,
 0x01, 0x0b, 0x03, 0x01, 0x0a, 0x11, 0x01, 0x00,
-0x15 };
+0x01 };
 
 /* identity response */
 static const uint8_t id_resp[] = {