(Github Comment Enhancer) Reply doesn't support task lists

[jerone]

This seems to only be an issue for task lists setup by someone else.

Test case (not linked intentionally):

• github.com/Intl: Build "English-only" binaries for the distribution. nodejs/node-v0.x-archive#7676#issuecomment-63399139

Test case working:

• new task, resulting in * <input class="task-list-item-checkbox" disabled="" type="checkbox">
• completed task, resulting in * <input class="task-list-item-checkbox" checked="" disabled="" type="checkbox">