xlsclient: unbreak build

Fixes http://autobuild.buildroot.net/results/4cb357a99de9e2c2940fbdfccb314aaef5891b6b



xlsclient nowadays needs libxcb and xcb-util, and update to 1.1.1, as
1.1.0 tarball was missing strnlen.h.

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>