default wiki clone url needs corrected

In the first/default wiki page, we need another "/" in the url (between the repo name and "wiki"), so that it ends with "repo/wiki/".

it currently reads:
{{{
Go ahead and try:

$ hg clone http://bitbucket.org/user/repowiki/\\
Wiki pages are normal files, with the .wiki extension. You can edit them locally, as well as creating new ones.
}}}

bitbucket rocks!