[evolution] remove gtkhtml version define as gtkhtml is not used anymore

[Olav Vitters <ovitters src gnome org>]

commit d5ac3cfcf151c1988d06120cd63f1c41c3aed504
Author: Olav Vitters <olav vitters nl>
Date:   Mon Jun 23 11:43:05 2014 +0200

    remove gtkhtml version define as gtkhtml is not used anymore

 configure.ac |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index e08fc28..efd6a76 100644
--- a/configure.ac
+++ b/configure.ac
@@ -45,7 +45,6 @@ m4_define([soup_minimum_version], [2.42])
 m4_define([soup_encoded_version], [SOUP_VERSION_2_42])
 
 m4_define([eds_minimum_version], [evo_version])
-m4_define([gtkhtml_minimum_version], [4.5.2])
 m4_define([gdk_pixbuf_minimum_version], [2.24.0])
 m4_define([gcr_minimum_version], [3.4])
 m4_define([enchant_minimum_version], [1.1.7])