Merge #522: Fix occasional mempool_packages failure

a88eae1 Fix occasional mempool_packages failure (Steven Roose)

Pull request description:

Tree-SHA512: 89c3880a184294b5708304c9add8936b65572af8f03033505d1961da58f705776a8f42a29e8815c0eab3ca84f4dac36bc1c22ab5697cf0675ce50ba4d23b00ff

Author: instagibbs

test/functional/mempool_packages.py

@@ -30,7 +30,7 @@ def chain_transaction(self, node, parent_txid, vout, value, fee, num_outputs):
         outputs = {}
         for i in range(num_outputs):
             outputs[node.getnewaddress()] = send_value
-        outputs["fee"] = fee
+        outputs["fee"] = value - (num_outputs * send_value)
         rawtx = node.createrawtransaction(inputs, outputs)
         signedtx = node.signrawtransactionwithwallet(rawtx)
         txid = node.sendrawtransaction(signedtx['hex'])