SMR should be enabled by default

The LISP service can send a Solicit-Map-Request control message to mapping change subscribers to notify them of a change event (see RFC6830, sec. 6.6.2 [1]). For OpenDaylight this feature is controlled by the lisp.smr configuration entry in etc/custom.properties, with the default being off. Due to the utility of the feature, users reasonable expect this to be on by default, and turned off explicitly only when circumstances require that.

[1] https://tools.ietf.org/html/rfc6830#section-6.6.2