Core/Updater: Fix mysql cli password prompt when password is empty.

* ref: http://community.trinitycore.org/topic/11510-world-server-bug-enter-password-to-update/

src/server/shared/Updater/DBUpdater.cpp

@@ -351,7 +351,9 @@ void DBUpdater<T>::ApplyFile(DatabaseWorkerPool<T>& pool, std::string const& hos
     // CLI Client connection info
     args.push_back("-h" + host);
     args.push_back("-u" + user);
-    args.push_back("-p" + password);
+
+    if (!password.empty())
+        args.push_back("-p" + password);
 
     // Check if we want to connect through ip or socket (Unix only)
 #ifdef _WIN32