core: use of Const for profile_key + replaced '@DEFAULT@' default profile_key by '@NONE@'

src/plugins/plugin_misc_quiz.py

@@ -18,6 +18,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 from sat.core.i18n import _
+from sat.core.constants import Const as C
 from logging import debug, info, warning, error
 from twisted.words.xish import domish
 from twisted.internet import protocol, defer, threads, reactor
@@ -175,7 +176,7 @@ class Quiz(object):
         yourturn_elt = mess.firstChildElement().addElement('your_turn')
         self.host.profiles[profile].xmlstream.send(mess)
 
-    def playerAnswer(self, player, referee, answer, profile_key='@DEFAULT@'):
+    def playerAnswer(self, player, referee, answer, profile_key=C.PROF_KEY_NONE):
         """Called when a player give an answer"""
         profile = self.host.memory.getProfileName(profile_key)
         if not profile: