little bugfix if config file is not correct

core/core.py

@@ -332,7 +332,9 @@ class GajimCore:
 						type = 'available'
 						if ev[2][0] == 'invisible':
 							type = 'invisible'
-						prio = str(self.cfgParser.tab[ev[1]]['priority'])
+						prio = 0
+						if self.cfgParser.tab[ev[1]].has_key('priority'):
+							prio = str(self.cfgParser.tab[ev[1]]['priority'])
 						con.sendPresence(type, prio, ev[2][0], ev[2][1])
 						self.hub.sendPlugin('STATUS', ev[1], ev[2][0])
 				#('MSG', account, (jid, msg))