* use GLib functions to write&read compose file
* trim trailing new-line characters from compose file
Signed-off-by: Steffen Jaeckel <jaeckel-floss@eyet-services.de>
In case we're not connected yet and press Alt+c a segfault occurred
since `conn.xmpp_conn` is dereferenced while it's still `NULL`.
Signed-off-by: Steffen Jaeckel <jaeckel-floss@eyet-services.de>