Unable to create child container from Hawtio when setting a system property

Issue

• When attempting to create a child container from Hawtio and setting a system property on the advance tab the following error occurs:

java.lang.IllegalArgumentException : Can not instantiate value of type [map type; class java.util.LinkedHashMap, [simple type, class java.lang.String] -> [map type; class java.util.Properties, [simple type, class java.lang.Object] -> [simple type, class java.lang.Object]]] from JSON String; no single-String constructor/factory method (through reference chain: io.fabric8.api.Builder["systemProperties"])