Fix for mismatched extern definition in wallet test classes which was breaking msvc linking.

src/wallet/test/accounting_tests.cpp

@@ -10,7 +10,7 @@
 
 #include <boost/test/unit_test.hpp>
 
-extern CWallet* pwalletMain;
+extern std::unique_ptr<CWallet> pwalletMain;
 
 BOOST_FIXTURE_TEST_SUITE(accounting_tests, WalletTestingSetup)
 

src/wallet/test/wallet_tests.cpp

@@ -19,7 +19,7 @@
 #include <boost/test/unit_test.hpp>
 #include <univalue.h>
 
-extern CWallet* pwalletMain;
+extern std::unique_ptr<CWallet> pwalletMain;
 
 extern UniValue importmulti(const JSONRPCRequest& request);
 extern UniValue dumpwallet(const JSONRPCRequest& request);