Clone epel10 branches with clone -B
    
    Running `fedpkg clone -B` relies on the configured branch regex to
    determine the branches to clone.  The current regex doesn't match EPEL
    branches with more that one digit.  We recently started having epel10
    branches, and in the future we'll also have epel10.0, epel10.1, and so
    forth.  This adjusts the regex to account for these branch names.
    
    Merges: https://pagure.io/fedpkg/pull-request/572
    
    Signed-off-by: Carl George <carlwgeorge@gmail.com>