Etag instead of ETag 2.6.1 IndividualNSInstance.robot
IndividualNSInstance.robot
https://forge.etsi.org/rep/nfv/api-tests/blob/2.6.1-fix-plu/SOL005/NSLifecycleManagement-API/IndividualNSInstance.robot
```
PUT Individual NSInstance - Method not implemented :: Test ID: 5.3...
Property 'Etag' does not exist in:
```
```
GET Information about an individual NS Instance :: Test ID: 5.3.2.2.2 | FAIL |
Expected property 'response headers Etag' was not found.
```
```
PATCH Individual NSInstance - Method not implemented :: Test ID: 5... | FAIL |
Expected property 'response headers Etag' was not found.
```
issue