Fix url regexp.

\d allows numbers from other digit systems, so urls like: http://demo.getpinry.com/१७/ are possible. This could lead to some nasty security issues in the future (ie. if you try to use pin number without using `int(...)`).

pinry/core/urls.py

@@ -30,7 +30,7 @@ urlpatterns = patterns('',
         name='tag-pins'),
     url(r'^pins/user/(?P<user>(\w|-)+)/$', TemplateView.as_view(template_name='core/pins.html'),
         name='user-pins'),
-    url(r'^(?P<pin>\d+)/$', TemplateView.as_view(template_name='core/pins.html'),
+    url(r'^(?P<pin>[0-9]+)/$', TemplateView.as_view(template_name='core/pins.html'),
         name='recent-pins'),
     url(r'^$', TemplateView.as_view(template_name='core/pins.html'),
         name='recent-pins'),