dev/core#1339 Dedupe screen check to carry across any data where the other contact...

dev/core#1339 Dedupe screen check to carry across any data where the other contact has none by default.

This change in default means that if the contact to be deleted has data in a field and the contact to be kept does not the
checkbox loads as checked by default (so it's easier to keep too much data but harder to lose some.)

https://lab.civicrm.org/dev/core/issues/1339

The user can override by unchecking - this is just what is set on screen load