camel-k: Delete knative warning when Knative is not installed

The operator prints periodically this info:

{"level":"info","ts":1623416979.434832,"logger":"camel-k","msg":"could not find any knative type in namespace camel, last error was: services.serving.knative.dev is forbidden: User \"system:serviceaccount:camel:camel-k-operator\" cannot list resource \"services\" in API group \"serving.knative.dev\" in the namespace \"camel\""}

It looks like an error, while it’s not. That log should be suppressed.