Scouter client crash under Linux

[ndgnuh]

Reproduce:

# run
GDK_SYNCHRONIZE=1 ./scouter.client/scouter
# input username/password and connect

The crash log:

Success to connect 127.0.0.1:6100 (direct)
[xcb] Unknown sequence number while processing reply
[xcb] Most likely this is a multi-threaded client and XInitThreads has not been called
[xcb] Aborting, sorry about that.
java: ../../src/xcb_io.c:725: _XReply: Assertion `!xcb_xlib_threads_sequence_lost' failed.