Win build fix

Thanks to @dizzisound https://github.com/VCVRack/VCV-Prototype/issues/66#issuecomment-1430090584

src/Prototype.cpp

@@ -504,7 +504,7 @@ struct Prototype : Module {
 		(void) std::system(command.c_str());
 #elif defined ARCH_WIN
 		std::string command = editorPath + " \"" + path + "\"";
-		std::wstring commandW = string::toWstring(command);
+		std::wstring commandW = string::UTF8toUTF16(command);
 		STARTUPINFOW startupInfo;
 		std::memset(&startupInfo, 0, sizeof(startupInfo));
 		startupInfo.cb = sizeof(startupInfo);