translations: update Czech translation

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
gui: do not pass const reference QString when a copy is needed

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
gui: #2678 fixed: remove new line characters from window title

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
imagelink: #2676 fixed: improve image links recognition

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
protocols: move roster service to roster dir

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