Editorial: use 'global' rather than 'this' in timer initialization steps

[Ms2ger]

There is no this value around at this point.

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/timers-and-user-prompts.html ( diff )

[annevk]

Nice! Could you also fix the other instance three steps down?

(Tiny bit on the fence as to whether this is editorial, but I suppose it's somewhat hard to misunderstand intent.)

[Ms2ger]

Done, thanks for catching that. I don't mind much either way about calling it editorial.