Reword the apology when web puzzles fail to load.

Reword the apology when web puzzles fail to load.

The old one was totally out of date (it mentioned typed arrays and a
specific set of browser versions against which the previous Emscripten
build had been tested).

Also, a couple of users in the last day or two have reported
mysterious failures of the WASM puzzles, which I haven't been able to
reproduce in the same version of the same browser. So something odd is
going on, and this seems like a good place to put suggestions about
what diagnostic information to send.