Remove padding input form ledger PSBT signing (#311)

Co-authored-by: Tim Man <tim@secretkeylabs.com>

ledger/psbt.ts

@@ -141,6 +141,7 @@ export async function signLedgerPSBT({
   const masterFingerPrint = await app.getMasterFingerprint();
 
   const { inputTotal, outputTotal } = getIoTotals(txn);
+  let addedPaddingInput = false;
 
   if (inputTotal < outputTotal) {
     // There is a bug in Ledger that if the inputs are greater than the outputs, then it will fail to sign
@@ -153,6 +154,7 @@ export async function signLedgerPSBT({
         amount: outputTotal - inputTotal,
       },
     });
+    addedPaddingInput = true;
   }
 
   if (
@@ -204,6 +206,12 @@ export async function signLedgerPSBT({
     }
   }
 
+  if (addedPaddingInput) {
+    // We inserted a dummy input to get around a Ledger bug, so we need to remove it
+    // @ts-expect-error: Expected error as inputs are private, but this is the only way to remove the input
+    txn.inputs.pop();
+  }
+
   if (finalize) {
     txn.finalize();
   }