plugin chat: fixed dropdown: dropdown was calling "open" each time a key was pressed, abd open is calling dismiss if dropdown is already opened. But dismiss is calling _real_dissmiss with a schedule, resulting in incoherent state and the dropdown not closed when expected. A check is now done to call "open" only when there is not already a dropdown, and to call dismiss when the text input is empty.

[DEFAULT]
bridge = pb
log_level = debug
log_fmt = #[%%(levelname)s][%%(name)s] %%(message)s

[cagou]
log_level = debug
log_fmt = [%%(levelname)s][%%(name)s] %%(message)s