Fix idle detection

Fixes #9149

gajim/common/idle.py

@@ -194,6 +194,7 @@ class IdleMonitor:
     def is_available(self):
         return self._idle_monitor is not None
 
+    @property
     def state(self):
         if not self.is_available():
             return IdleState.UNKNOWN

gajim/gui_interface.py

@@ -1116,7 +1116,7 @@ class Interface:
         app.block_signed_in_notifications[account] = True
         connected = obj.conn.connected
 
-        if idle.Monitor.is_unknown() and connected in (2, 3):
+        if not idle.Monitor.is_unknown() and connected in (2, 3):
             # we go online or free for chat, so we activate auto status
             app.sleeper_state[account] = 'online'
         elif not ((idle.Monitor.is_away() and connected == 4) or \