Fix the client crash when you open the missions window

[MillhioreBT]

Pull Request Prelude

• I have followed [proper The Forgotten Server code styling][code].
• I have read and understood the [contribution guidelines][cont] before making this PR.
• I am aware that this PR may be closed if the above-mentioned criteria are not fulfilled.

Changes Proposed

The client 12.81 now needs the index of the mission that is sent to him, I do not know if it is the best way or if we need to identify the missions in another way that is not the index of the list

Issues addressed: Nothing!

[Zbizu]

You may track quests progress now. This is why it got an extra value. Overall quest log should have been rewritten, but I remember that the maintainers desire to keep compatibility blocked the pr in the past.

It's ok for now to add a placeholder though.

[omarcopires]

Maybe it's better to look this way rather than a partial solution, of course it's just a suggestion, but it would be interesting if you bring us your version of the code.

If possible take a look at this:
igorzerah/optimized_forgottenserver@7b23b35
igorzerah/optimized_forgottenserver@63503e1
igorzerah/optimized_forgottenserver@c8f4d42

[EPuncker]

Indeed there is a client crash (you can test it by having a non empty quest log), and this code does fix it.

[ranisalt]

And this has broken the other way around to OTClient 😆