Hawtio-log-osgi: Avoid using of deprecated methods with Jackson objectMapper

In Hawtio we use Jackson 2.7.x

In particular in hawtio-log-osgi we are using a method deprecated in 2.7.x and remove in 2.9.x. Since there are Karaf features in Camel using Jackson 2.9.x, the combination of the two version can create noSuchMethodException, so we need to avoid the use of deprecated method where we can.

The main problem is here https://github.com/hawtio/hawtio/blob/2.x/hawtio-log-osgi/src/main/java/io/hawt/log/osgi/LogQuery.java#L25