Clarify the log message for unknown Wii Menu regions

Saying just "title" made it seem like we are showing the title
ID, but what we actually are showing is the title version.

Source/Core/DiscIO/Enums.cpp

@@ -183,7 +183,7 @@ std::string GetSysMenuVersionString(u16 title_version)
     region_letter = "K";
     break;
   case Region::UNKNOWN_REGION:
-    WARN_LOG(DISCIO, "Unknown Region for title: %u", title_version);
+    WARN_LOG(DISCIO, "Unknown region for Wii Menu version %u", title_version);
     break;
   }