Update to abortcontroller-polyfill 1.4.0 (closes #6996)
Update to abortcontroller-polyfill 1.4.0
(closes #6996)

morray/iD,openstreetmap/iD,openstreetmap/iD,kartta-labs/iD,kartta-labs/iD,morray/iD,openstreetmap/iD,kartta-labs/iD