Revert "Keep some original fields on decrypted event"
Revert "Keep some original fields on decrypted event"

This reverts commit 680a05dbe38dbb0efd7d061d78b0a0797515e3ad.

matrix-org/matrix-ios-sdk,matrix-org/matrix-ios-sdk,matrix-org/matrix-ios-sdk,matrix-org/matrix-ios-sdk,matrix-org/matrix-ios-sdk