Use `connection.disabled` to prevent dragging from breaking a relation (closes #4921)
Use `connection.disabled` to prevent dragging from breaking a relation
(closes #4921)

AndreasHae/iD,kartta-labs/iD,ngageoint/hootenanny-ui,mapmeld/iD,ngageoint/hootenanny-ui,morray/iD,AndreasHae/iD,ngageoint/hootenanny-ui,kartta-labs/iD,morray/iD,kartta-labs/iD,digidem/iD,openstreetmap/iD,mapmeld/iD,openstreetmap/iD,mapmeld/iD,openstreetmap/iD,AndreasHae/iD,digidem/iD