[O] Replace deprecated org-set-local by setq-local in the documentation

[Loïc Estève]

Hi,

looks like org-set-local does not exist any more but it is still 
featured in the documentation.

I have the change in a branch on github:
https://github.com/lesteve/org-mode/compare/remove-org-set-local-from-doc

Cheers,
Loïc