bug: Update ApisixRoute has dirty configuration

[gxthrj]

Issue description

Apply ApisixRoute one by one cause dirty configuration
step 1:

apiVersion: apisix.apache.org/v2alpha1
kind: ApisixRoute
metadata:
  name: httpbin-route
  namespace: xxx
spec:
  http:
  - name: rule1
    match:
      hosts:
      - httpbin.com
      paths:
      - /ip
    backends:
    - serviceName: httpbin-service-e2e-test
      servicePort: 80
      weight: 50
    - serviceName: httpbin-service-e2e-test-v2
      servicePort: 80
      weight: 100

The route in APISIX like this:

{"action":"get","node":{"nodes":[{"modifiedIndex":144,"value":{"priority":0,"status":1,"plugins":{"traffic-split":{"rules":[{"weighted_upstreams":[{"weight":100,"upstream_id":"cd3dc953"},{"weight":50}],"match":[{"vars":[["server_port",">",0]]}]}]}},"id":"3fc92fca","create_time":1617946799,"update_time":1617946924,"name":"szydpoc_httpbin-route_rule1","hosts":["httpbin.com"],"uris":["\/ip"],"desc":"szydpoc_httpbin-route_rule1","upstream_id":"d678a7ac"},"createdIndex":142,"key":"\/apisix\/routes\/3fc92fca"}],"key":"\/apisix\/routes","dir":true},"count":"2"}

step 2:

kubectl apply -f - <<EOF
apiVersion: apisix.apache.org/v2alpha1
kind: ApisixRoute
metadata:
  name: httpbin-route
  namespace: xxx
spec:
  http:
  - name: rule1
    priority: 1
    match:
      hosts:
      - httpbin.com
      paths:
      - /ip
    backend:
      serviceName: httpbin-service-e2e-test
      servicePort: 80
  - name: rule2
    priority: 2
    match:
      hosts:
      - httpbin.com
      paths:
      - /ip
      exprs:
      - subject:
          scope: Cookie
          name: X-Foo
        op: Equal
        value: v2
    backend:
      serviceName: httpbin-service-e2e-test-v2
      servicePort: 80
EOF

The route in APISIX like this, the plugin traffic-split should be removed.

{"action":"get","node":{"nodes":[{"modifiedIndex":144,"value":{"priority":0,"status":1,"plugins":{"traffic-split":{"rules":[{"weighted_upstreams":[{"weight":100,"upstream_id":"cd3dc953"},{"weight":50}],"match":[{"vars":[["server_port",">",0]]}]}]}},"id":"3fc92fca","create_time":1617946799,"update_time":1617946924,"name":"xxx_httpbin-route_rule1","hosts":["httpbin.com"],"uris":["\/ip"],"desc":"xxx_httpbin-route_rule1","upstream_id":"d678a7ac"},"createdIndex":142,"key":"\/apisix\/routes\/3fc92fca"}],"key":"\/apisix\/routes","dir":true},"count":"2"}

[tokers]

The route in step1 doesn't contain traffic-split?

[gxthrj]

The route in step1 doesn't contain traffic-split?

mistake, I will modify the spec of this issue.

[tokers]

This bug is due to we use PATCH when updating, we should use PUT instead.