Removed exported test function from release build

OSC2AHK/dllmain.h

@@ -24,9 +24,11 @@ extern "C" DLLEXPORT int close(unsigned int clearListeners = 1);
 extern "C" DLLEXPORT int addListener(LPCSTR address, unsigned int messageID, unsigned int dataType = OSC_TYPE_ALL);
 extern "C" DLLEXPORT int removeListener(LPCSTR address);
 extern "C" DLLEXPORT char* getStringData(char* targetString, unsigned int targetSize, unsigned int StringID);
-extern "C" DLLEXPORT int testMsg(HWND windowHandle, unsigned int messageID);
 int handleOscMsg(const osc::ReceivedMessage& m);
 bool isMatchingOscType(unsigned int msgType, unsigned int listenerTypeField);
 unsigned int getOscType(osc::ReceivedMessage::const_iterator arg);
 void removeStoredString(int stringId);
 int addStoredString(std::string theString);
+#ifdef _DEBUG
+extern "C" DLLEXPORT int testMsg(HWND windowHandle, unsigned int messageID);
+#endif