RoutingFunction logging regarding resolved function should be debug level.

[bart-vanhaute-trimble]

In the current implementation of RoutingFunction, every time a route is executed, a log statement regarding resolution of a function using definition or using an expression is done at level INFO. In my opinion, this is not very interesting, exception when debugging your routing configuration. It would be better to log this at level DEBUG. I know I can change logging levels for this class.