Merge #12150: Fix ListCoins test failure due to unset g_address_type, g_change_type

f765bb3788 Fix ListCoins test failure due to unset g_address_type, g_change_type (Russell Yanofsky)

Pull request description:

  New global variables were introduced in #11403 and not setting them causes:

  ```
  test_bitcoin: wallet/wallet.cpp:4199: CTxDestination GetDestinationForKey(const CPubKey&, OutputType): Assertion `false' failed.
  unknown location(0): fatal error in "ListCoins": signal: SIGABRT (application abort requested)
  ```

  It's possible to reproduce the failure reliably by running:

  ```
  src/test/test_bitcoin --log_level=test_suite --run_test=wallet_tests/ListCoins
  ```

  Failures happen nondeterministically because boost test framework doesn't run tests in a specified order, and tests that run previously can set the global variables and mask the bug.

  Example travis failure: https://travis-ci.org/bitcoin/bitcoin/builds/327642495

Tree-SHA512: 3e0875716f66bc0304cf92a26457e6b54ecfe15ed962f4343577b05fc56bb577554422b7f53949ad6085ac5798ad7816b8176c5b01e050ddbfbb925d2732767a

src/wallet/test/wallet_tests.cpp

@@ -602,6 +602,8 @@ public:
     {
         CreateAndProcessBlock({}, GetScriptForRawPubKey(coinbaseKey.GetPubKey()));
         ::bitdb.MakeMock();
+        g_address_type = OUTPUT_TYPE_DEFAULT;
+        g_change_type = OUTPUT_TYPE_DEFAULT;
         wallet.reset(new CWallet(std::unique_ptr<CWalletDBWrapper>(new CWalletDBWrapper(&bitdb, "wallet_test.dat"))));
         bool firstRun;
         wallet->LoadWallet(firstRun);