Description of problem:

The `parseIPList` function in `pkg/router/template/template_helper.go` logs at verbosity level `V(0)` when it receives an empty IP allowlist string. Since `V(0)` messages are always emitted regardless of log verbosity settings, this causes massive log spam on clusters with many routes that don't have `haproxy.router.openshift.io/ip_allowlist` annotations.

Version-Release number of selected component (if applicable):

    N/A

How reproducible: Always

Steps to Reproduce:

    1. Deploy OKD/OpenShift 4.x cluster
    2. Create multiple routes without `ip_allowlist` or `ip_whitelist` annotations
    3. Observe router pod logs: `oc logs -n openshift-ingress -l ingresscontroller.operator.openshift.io/deployment-ingresscontroller=default`
    4. Trigger a config reload (create/modify any route, service, or endpoint)
    5. Observe flood of "parseIPList empty list found" messages

Actual results:

On a cluster with 822 routes (none with allowlist annotations), every config reload generates {}822 log messages{}:

I0108 15:56:42.194350  1 template_helper.go:370] "msg"="parseIPList empty list found" "logger"="template"
I0108 15:56:42.194433  1 template_helper.go:370] "msg"="parseIPList empty list found" "logger"="template"
I0108 15:56:42.194511  1 template_helper.go:370] "msg"="parseIPList empty list found" "logger"="template"
... (repeated 822 times per reload)

Expected results:

An empty/absent IP allowlist is the normal, expected configuration for most routes. This should not generate a log message at V(0). The log level should be V(7) or higher (debug/trace level) to match other informational messages in the same function.

Additional info:

Also filed github issue https://github.com/openshift/router/issues/708.