configure: Lower kbproto requirement to 1.0.4

There's nothing in 1.0.5 that we need.
diff --git a/configure.ac b/configure.ac
index 6b695b9..e6a8f15 100644
--- a/configure.ac
+++ b/configure.ac
@@ -70,7 +70,7 @@
 fi
 
 # Obtain protocols headers include directives
-PKG_CHECK_MODULES([X11], [xproto kbproto >= 1.0.5])
+PKG_CHECK_MODULES([X11], [xproto kbproto >= 1.0.4])
 
 # Obtain the path to the X Window System Core Protocol
 AC_MSG_CHECKING([for X11 includedir])