txbuilder: add missing signature P2MS fixture

test/fixtures/transaction_builder.json

@@ -1917,6 +1917,29 @@
           }
         ]
       },
+      {
+        "description": "Incomplete Transaction P2SH(P2MS 2/3), missing signature",
+        "exception": "Not enough signatures provided",
+        "network": "testnet",
+        "inputs": [
+          {
+            "txId": "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff",
+            "vout": 0,
+            "signs": [
+              {
+                "keyPair": "91avARGdfge8E4tZfYLoxeJ5sGBdNJQH4kvjJoQFacbgwmaKkrx",
+                "redeemScript": "OP_2 0479be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8 04c6047f9441ed7d6d3045406e95c07cd85c778e4b8cef3ca7abac09b95c709ee51ae168fea63dc339a3c58419466ceaeef7f632653266d0e1236431a950cfe52a 04f9308a019258c31049344f85f89d5229b531c845836f99b08601f113bce036f9388f7b0f632de8140fe337e62a37f3566500a99934c2231b6cb9fd7584b8e672 OP_3 OP_CHECKMULTISIG"
+              }
+            ]
+          }
+        ],
+        "outputs": [
+          {
+            "script": "OP_DUP OP_HASH160 aa4d7985c57e011a8b3dd8e0e5a73aaef41629c5 OP_EQUALVERIFY OP_CHECKSIG",
+            "value": 1000
+          }
+        ]
+      },
       {
         "description": "Duplicate transaction outs",
         "exception": "Duplicate TxOut: ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff:0",