[IOS-XE] Parser for "show macsec summary" does not work

[ChristopherJHart]

The parser for IOS-XE's show macsec summary command does not work.

Sample CLI output:

R2#show macsec summary

 MACsec Capable Interface                Extension              Installed Rx SC
---------------------------------------------------------------------------------
 TenGigabitEthernet0/0/0                 One tag-in-clear                 1
 TenGigabitEthernet0/0/1                 One tag-in-clear
 TenGigabitEthernet0/0/2                 One tag-in-clear
 TenGigabitEthernet0/0/3                 One tag-in-clear
 TenGigabitEthernet0/0/4                 One tag-in-clear                 1
 TenGigabitEthernet0/0/5                 One tag-in-clear
 TenGigabitEthernet0/0/6                 One tag-in-clear
 TenGigabitEthernet0/0/7                 One tag-in-clear
 TenGigabitEthernet0/0/8                 One tag-in-clear
 TenGigabitEthernet0/0/9                 One tag-in-clear
 TenGigabitEthernet0/0/10                One tag-in-clear
 TenGigabitEthernet0/0/11                One tag-in-clear

 MACsec Enabled Interface         Receive SC   VLAN
-----------------------------------------------------
 TenGigabitEthernet0/0/0.10   :        1       10
 TenGigabitEthernet0/0/1.10   :        1       10

Actual return data does not have any meaningful information:

{
    'interfaces': {
    },
}