Set delegated addr to nil (#280)

Co-authored-by: zenground0 <[email protected]>

Author: ZenGround0

builtin/v14/migration/top.go

@@ -127,9 +127,9 @@ func MigrateStateTree(ctx context.Context, store cbor.IpldStore, newManifestCID
 			Balance:    f090OldAct.Balance,
 
 			// changed
-			Code:             newAccountCodeCID,
-			Head:             h,
-			DelegatedAddress: &f090ID,
+			Code: newAccountCodeCID,
+			Head: h,
+			// DelegatedAddress: nil,
 		})
 	}
 	if err := f090Migration(actorsOut); err != nil {