contacts.py: get_contact_from_full_jid not to raise exceptions on bare jids

src/common/contacts.py

@@ -236,8 +236,12 @@ class Contacts:
 	def get_contact_from_full_jid(self, account, jid):
 		'''we will split the jid into bare jid and resource part,
 		then get proper contact.'''
+		try:
 			barejid, resource=jid.split('/',1)
 			return self.get_contact(account, barejid, resource)
+		except ValueError: # no resource causes split to fail
+			return None # how to handle that case?
+
 	def get_highest_prio_contact_from_contacts(self, contacts):
 		if not contacts:
 			return None