Fix bug introduced in 7.5 with interact menu on self.

[Chryssie]

This should fix the right-click menu issue. It appears that OnlineGetUserItems() returns nil in some cases causing the not onlineitems[ware] check in menu_interactmenu.lua on line 5097 (of the core game, not the mod) to throw. Not sure if this is an Egosoft bug or something downstream of delaying the render/draw but this does fix the issue. May be possible to fix it differently though in a better way.

This just explictly adds onlineitems == nil or check to guard against that case.

[Chryssie]

Due note, I can't figure out how to get the the plugins working locally with this setup so I can't test it as-is. However, I have been able to test it with the addition of #26 which I can get working locally and both the new (a9312cc) and the previous change (ad7807f) resolve the issue, although the new change doesn't require duplicating a bunch of Egosoft code.

[Chryssie]

Unfortunately overriding the function causes an error, may need to revert to ad7807f.

[=ERROR=] 15.29 D:/SteamLibrary/steamapps/common/X4 Foundations/extensions/sn_mod_support_apis/ui/OnlineGetUs...(6): (from presentation 'ui/widget/presentations/widget_fullscreen/widget_fullscreen.bgf') Restricted function OnlineGetUserItems() called from non-verified source 'extensions/sn_mod_support_apis/ui/OnlineGetUserItemsPatch.lua'! Aborting call!