chat: better variable name

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
chat: remove unconfigurable variable

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
chat: #2696 fixed: do not open chat window when message is sent for Gadu-Gadu multilogon

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>