[gtk-theme-engine-clearlooks] Fix distcheck

[Matthias Clasen <matthiasc src gnome org>]

commit 1e6641c1ee9ad20f0e23229ee490a59ee4e61fd2
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon Dec 6 22:40:17 2010 -0500

    Fix distcheck

 src/Makefile.am |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/Makefile.am b/src/Makefile.am
index 0b95e3d..47464ea 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -53,7 +53,7 @@ EXTRA_DIST = 				\
 	clearlooks_typebuiltin.c.template \
 	clearlooks_typebuiltin.h.template
 
-EXTRA_DIST = engine.symbols
+EXTRA_DIST += engine.symbols
 
 -include $(top_srcdir)/git.mk