$OpenBSD$

fix builds using Makefile.simple

--- src/ocp-indent-lib.mllib.orig	Sun Mar 29 20:10:03 2015
+++ src/ocp-indent-lib.mllib	Sun Mar 29 20:10:10 2015
@@ -1,4 +1,3 @@
-Approx_common
 Approx_tokens
 Approx_lexer
 Compat
