[1.2.X] Fixed #14381 -- Clarified exception handling when instantiati…

…ng Routers. Thanks to dauerbaustelle for the suggestion and patch.

Backport of r14005 from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@14008 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/utils.py

@@ -111,9 +111,11 @@ def __init__(self, routers):
                 except ImportError, e:
                     raise ImproperlyConfigured('Error importing database router %s: "%s"' % (klass_name, e))
                 try:
-                    router = getattr(module, klass_name)()
+                    router_class = getattr(module, klass_name)
                 except AttributeError:
                     raise ImproperlyConfigured('Module "%s" does not define a database router name "%s"' % (module, klass_name))
+                else:
+                    router = router_class()
             else:
                 router = r
             self.routers.append(router)