Fix regression introduced in [9727]. Do not fail if the jid line contain 'Enter

JID or Contact name' or something at opening.

src/history_window.py

@@ -156,6 +156,9 @@ class HistoryWindow:
 		keys = self.completion_dict.keys()
 		# Move the actual jid at first so we load history faster
 		actual_jid = self.jid_entry.get_text().decode('utf-8')
+		if actual_jid.find('@') > 0:
+			# it's not 'Enter JID or Contact name' or something, but a real jid,
+			# we can really move it at first
 			if actual_jid in keys:
 				keys.remove(actual_jid)
 				keys.insert(0, actual_jid)