ns2: add TC_sns_sgsn_add_change_del similiar to the bss side

1. do SNS configuration
2. add a bind
3. receive the SNS_ADD
4. before answering the SNS_ADD, change the weight via vty and remove the bind

Change-Id: I1a3d2273279f3def0d225ba78d400fb52a958c64
1 file changed