fix e2e testfile

Signed-off-by: kkk777-7 <kota.kimura0725@gmail.com>

Author: kkk777-7

test/e2e/testdata/backendtrafficpolicy-listenerset.yaml

@@ -242,7 +242,7 @@ spec:
       - type: Range
         range:
           start: 421
-          end: 421
+          end: 422
     response:
       statusCode: 500
 ---