Use custom reward address in mnvaults.py.

Custom reward addresses are one of the core features needed for
proper masternode vaults.  With them implemented now, we can update
the mnvaults.py test (resolving two FIXME's in there) to actually make
use of an explicit reward address so that the masternode rewards are
received and not lost (as we want them to be in practice).

Author: domob1812

divi/qa/rpc-tests/mnvaults.py

@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# Copyright (c) 2020 The DIVI developers
+# Copyright (c) 2020-2021 The DIVI developers
 # Distributed under the MIT/X11 software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -125,9 +125,8 @@ def fund_vault (self):
     self.unvaultTx = signed["hex"]
 
     self.setup_masternode(2,1,"mn","copper",{"txhash":txid,"vout":vout})
+    self.setup[1].cfg.rewardAddr = self.nodes[0].getaddress ("reward")
     self.cfg = self.setup[1].cfg
-    # FIXME: Use reward address from node 0.
-    self.cfg.rewardAddr = addr
     self.stop_masternode_daemons()
     self.start_masternode_daemons(updateMockTime=True)
     self.connect_masternodes_to_peers(range(3,7),updateMockTime=True)
@@ -204,6 +203,9 @@ def get_payments (self):
       self.advance_time (10)
       time.sleep(0.01)
 
+    # Mine some blocks normally to make sure the rewards are mature.
+    self.mine_blocks (20)
+
     # Check that some payments were made.
     winners = self.nodes[3].getmasternodewinners ()
     found = False
@@ -213,7 +215,9 @@ def get_payments (self):
         break
     assert_equal (found, True)
 
-    # FIXME: Check in wallet when we have a custom reward address.
+    # The payments should have been received at the reward address
+    # and in particular not be lost in the "destroyed" vault.
+    assert_greater_than (self.nodes[0].getbalance ("reward"), 0)
 
   def unvault (self):
     print ("Unvaulting the funds...")