Fix default class_id parameter for isChallengeCleared

`ChallengeAttempts::isChallengeCleared()` uses '*' as a default value for the `class_id` parameter. This wildcard operator only works with `LIKE`.

The second commit fixes this. The first one sets the same end lines for the whole file.
Before this PR, this file seemed to have several kind of end lines. I didn't manage to edit the file without changing them (they seem to change automatically under Windows as well as under Linux). I made two commits to allow you to see just my fix in the second one.
I came across this issue of heterogeneous end lines in several file.