Revert "more robust isDelegateSigner for swift orders"

This reverts commit 2d4e30b.

Author: moosecat2

sdk/src/driftClient.ts

@@ -6639,21 +6639,14 @@ export class DriftClient {
 			readablePerpMarketIndex: marketIndex,
 		});
 
+		const isDelegateSigner = takerInfo.signingAuthority.equals(
+			takerInfo.takerUserAccount.delegate
+		);
+
 		const borshBuf = Buffer.from(
 			signedSignedMsgOrderParams.orderParams.toString(),
 			'hex'
 		);
-
-		const isDelegateSigner = borshBuf
-			.slice(0, 8)
-			.equals(
-				Uint8Array.from(
-					Buffer.from(
-						sha256('global' + ':' + 'SignedMsgOrderParamsDelegateMessage')
-					).slice(0, 8)
-				)
-			);
-
 		try {
 			const { signedMsgOrderParams } = this.decodeSignedMsgOrderParamsMessage(
 				borshBuf,