Call correct clone subroutine

We have changed the meaning of clone_user_repos so that it only clones
the repositories of one user. We did however pass it a list of users.
Thus the program only cloned the repositories of the first user in the
list. Fix this problem by calling the correct subroutine, which accepts
a list of users.

Signed-off-by: Marcus Karlsson <mk@acc.umu.se>