Export->Package crashes on New Quest

[Asuna Yuuki Nagato]

ZQuest Classic Editor
Version: 2.55 Nightly (Alpha 118/119)
Tag: 2.55.0 Nightly (Alpha 118/119)
Build Date: 22nd January, 2024 at @ 21:17:49 EST
Dev Signoff: Unsigned
QR:##B343AFAF01C281A00DA58A4211A608DFDF080001362A0410FC5306FE2A274100381B02044031300000065824C00000000000D0032301000000000000000000000000000000000000000000000000000034866C3140320200000000000000000000000000##

Steps to recreate:

1. Launch zeditor.exe
2. File->New
3. File->Export->Package

Unhandled exception at 0x00007FFCE271CF19 in zeditor.exe: Microsoft C++ exception: std::filesystem::filesystem_error at memory location 0x0000009B212FB740.

[Asuna Yuuki Nagato]

I have fixed this by adding this block before the call to package_create in onExport_Package() in zq_misc.cpp:

	if (strlen(filepath) == 0){
		InfoDialog("Can't export untitled quest", "Please save the quest before exporting").show();
		return D_O_K;
	}

Please review.