ipsec-op: T3341: Fix for resetting peer tunnel

[sever-sever]

Change Summary

VyOS 1.2
The current resetting is affected for parent SA, in that case
all child SA's are resetting (if one peer have a several tunnels)
This commit fixes such behavior for correct resetting child SA's.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Code style update (formatting, renaming)
• Refactoring (no functional changes)
• Migration from an old Vyatta component to vyos-1x, please link to related PR inside obsoleted component
• Other (please describe):

Related Task(s)

• https://phabricator.vyos.net/T3341

Component(s) name

vpn

How to test

Configure peer with more than 1 tunnel and reset ipsec tunnel 0

vyos@r12-lts:~$ reset vpn ip
ipsec-peer     ipsec-profile  
vyos@r12-lts:~$ reset vpn ipsec-peer 192.0.2.1 tunnel 0
Resetting tunnel 0 with peer 192.0.2.1...
vyos@r12-lts:~$ 

Check that only tunnel 0 was reset:

vyos@r12-lts:~$ sudo swanctl -l
peer-192.0.2.1-tunnel-0: #1, ESTABLISHED, IKEv1, 2667703e29fa2fc6_i* bd71dc68a6d64e59_r
  local  '192.0.2.2' @ 192.0.2.2[500]
  remote '192.0.2.1' @ 192.0.2.1[500]
  AES_CBC-256/HMAC_SHA1_96/PRF_HMAC_SHA1/MODP_1024
  established 167s ago, reauth in 2677s
  peer-192.0.2.1-tunnel-1: #5, reqid 2, INSTALLED, TUNNEL, ESP:AES_CBC-256/HMAC_SHA1_96/MODP_1024
    installed 167s ago, rekeying in 605s, expires in 1633s
    in  c8d7a4ef,      0 bytes,     0 packets
    out c35351b1,      0 bytes,     0 packets
    local  10.1.2.0/24
    remote 10.2.2.0/24
  peer-192.0.2.1-tunnel-2: #6, reqid 3, INSTALLED, TUNNEL, ESP:AES_CBC-256/HMAC_SHA1_96/MODP_1024
    installed 167s ago, rekeying in 559s, expires in 1633s
    in  c8feb502,      0 bytes,     0 packets
    out ca5330a6,      0 bytes,     0 packets
    local  10.1.3.0/24
    remote 10.2.3.0/24
  peer-192.0.2.1-tunnel-0: #7, reqid 4, INSTALLED, TUNNEL, ESP:AES_CBC-256/HMAC_SHA1_96/MODP_1024
    installed 4s ago, rekeying in 815s, expires in 1796s
    in  c4637883,      0 bytes,     0 packets
    out c2d867ac,      0 bytes,     0 packets
    local  10.1.1.0/24
    remote 10.2.1.0/24