Remove warning whenever we receive an unknown WAF address (#7482)

These happens whenever we receive rules for an address that is not
supported by the current version, which is bound to happen for
previously released tracers. This has proved to be non-helpful so far,
and confusing to customers. Other tracers are not logging this either.

Author: smola

dd-java-agent/appsec/src/main/java/com/datadog/appsec/powerwaf/PowerWAFModule.java

@@ -387,8 +387,6 @@ private static Collection<Address<?>> getUsedAddresses(PowerwafContext ctx) {
       Address<?> address = KnownAddresses.forName(addrKey);
       if (address != null) {
         addressList.add(address);
-      } else {
-        log.warn("WAF has rule against unknown address {}", addrKey);
       }
     }