…sis config

primary destination is duplicated on both virtual service routes when setting match rules as per the [istio a/b testing](https://docs.flagger.app/tutorials/istio-ab-testing) tutorial:
```yaml
  http:
  - match:
    - headers:
        x-header-1:
          exact: Test_from_DEVs
    route:
    - destination:
        host: podinfo-primary
      weight: 50
    - destination:
        host: podinfo-canary
      weight: 50
  - route:
     - destination:
         host: podinfo-primary
        weight: 50
```
this PR removes the primary destination from canary route to generate and update the virtual service without the duplicate destination:
```yaml
  http:
  - match:
    - headers:
        x-header-1:
          exact: Test_from_DEVs
    route:
    - destination:
        host: podinfo-canary
      weight: 50
  - route:
    - destination:
        host: podinfo-primary
       weight: 50
```

Signed-off-by: luisr-escobar <[email protected]>

Signed-off-by: luisr-escobar <[email protected]>

Signed-off-by: luisr-escobar <[email protected]>

Signed-off-by: luisr-escobar <[email protected]>