local variable 'restrict' referenced before assignment

[Enlik]

Looks like it was broken in 27f61fd. :)

# pmerge -NuDav --debug
 * Scanning for changed USE...
Unhandled Exception occurred:
Traceback follows:
  File "/usr/lib/python2.7/site-packages/pkgcore/util/commandline.py", line 839, in main
    exitstatus = main_func(options, out, err)
  File "/usr/lib/python2.7/site-packages/pkgcore/scripts/pmerge.py", line 474, in main
    for inst_pkg in installed_repos.itermatch(restrict):

Error was:
 local variable 'restrict' referenced before assignment

[radhermit]

Note that this doesn't actually make the -N option work as expected in all cases, but that's a resolver issue.