configure.ac: Require inputproto 2.3

This picks up support for Xi pointer barriers in the protocol.
Signed-off-by: Robert Morell <rmorell@nvidia.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

configure.ac

@@ -788,7 +788,7 @@ XPROTO="xproto >= 7.0.22"
 RANDRPROTO="randrproto >= 1.4.0"
 RENDERPROTO="renderproto >= 0.11"
 XEXTPROTO="xextproto >= 7.1.99"
-INPUTPROTO="inputproto >= 2.2.99.1"
+INPUTPROTO="inputproto >= 2.3"
 KBPROTO="kbproto >= 1.0.3"
 FONTSPROTO="fontsproto"
 FIXESPROTO="fixesproto >= 5.0"