stgit.namelength is an integer

stgit.namelength is an integer

Interpret stgit namelength as an integer, else the use of
name_len will fail with

  File "/usr/lib/python2.5/site-packages/stgit/utils.py", line 206, in patch_name_from_msg
    return re.sub('[\W]+', '-', subject_line).strip('-')[:name_len]
TypeError: slice indices must be integers or None or have an __index__ method

Signed-off-by: Pete Wyckoff <pw@padd.com>
Signed-off-by: Karl Hasselström <kha@treskal.com>