libxcb: relax host-python regexp

Some python versions print x.y rather than x.y.z as version number, so
make regexp more robust.

Reported-by: Paulius Zaleckas <paulius.zaleckas@gmail.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/x11r7/libxcb/libxcb.mk

@@ -13,7 +13,7 @@ LIBXCB_AUTORECONF = NO
 LIBXCB_LIBTOOL_PATCH = NO
 LIBXCB_DEPENDENCIES = host-libxslt pthread-stubs xcb-proto xlib_libXdmcp xlib_libXau
 LIBXCB_CONF_ENV = STAGING_DIR="$(STAGING_DIR)"
-HOST_PYTHON_VERSION=$(shell python --version 2>&1 | sed 's/Python \(2\.[0-9]\)\..*/\1/')
+HOST_PYTHON_VERSION=$(shell python --version 2>&1 | sed 's/Python \([0-9]\.[^\.]\).*/\1/')
 LIBXCB_MAKE_OPT = XCBPROTO_XCBINCLUDEDIR=$(STAGING_DIR)/usr/share/xcb XCBPROTO_XCBPYTHONDIR=$(STAGING_DIR)/usr/lib/python$(HOST_PYTHON_VERSION)/site-packages
 
 $(eval $(call AUTOTARGETS,package/x11r7,libxcb))