Merge pull request #825 from sipa/fix_822

Fix #822: use free instead of delete

src/bitcoinrpc.cpp

@@ -1561,7 +1561,7 @@ void ThreadCleanWalletPassphrase(void* parg)
             if (nWalletUnlockTime < nMyWakeTime)
                 nWalletUnlockTime = nMyWakeTime;
         }
-        free(parg);
+        delete (int*)parg;
         return;
     }