configure: Require wayland-server 1.2.90

Make sure we look for a recent enough version of wayland-server for
the new wl_seat release requests.
diff --git a/configure.ac b/configure.ac
index 66495be..3767d69 100644
--- a/configure.ac
+++ b/configure.ac
@@ -55,7 +55,7 @@
 
 AC_CHECK_FUNCS([mkostemp strchrnul initgroups])
 
-COMPOSITOR_MODULES="wayland-server >= 1.1.90 pixman-1"
+COMPOSITOR_MODULES="wayland-server >= 1.2.90 pixman-1"
 
 AC_ARG_ENABLE(egl, [  --disable-egl],,
               enable_egl=yes)