bitcoin-tx: Reject + sign in vout parsing

test/util/data/bitcoin-util-test.json

@@ -264,6 +264,14 @@
     "error_txt": "error: invalid TX sequence id 'abcdef00'",
     "description": "Try to make invalid input replaceable"
   },
+  { "exec": "./bitcoin-tx",
+    "args":
+    ["-create",
+     "in=5897de6bd6027a475eadd57019d4e6872c396d0716c4875a5f1a6fcfdf385c1f:+0"],
+    "return_code": 1,
+    "error_txt": "error: invalid TX input vout",
+    "description": "Tests the check for an invalid vout value when adding an input"
+  },
   { "exec": "./bitcoin-tx",
     "args":
     ["-create",