[gtksourceview] Add "both" as a known css value

[Paolo Borelli <pborelli src gnome org>]

commit 55991708d45fc8f541b5a06489099517a750ce45
Author: Paolo Borelli <pborelli gnome org>
Date:   Sun Jan 4 18:46:51 2015 +0100

    Add "both" as a known css value
    
    https://bugzilla.gnome.org/show_bug.cgi?id=741253

 data/language-specs/css.lang |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/data/language-specs/css.lang b/data/language-specs/css.lang
index dd71660..63c65b1 100644
--- a/data/language-specs/css.lang
+++ b/data/language-specs/css.lang
@@ -303,6 +303,7 @@
       <keyword>block</keyword>
       <keyword>bolder</keyword>
       <keyword>bold</keyword>
+      <keyword>both</keyword>
       <keyword>bottom</keyword>
       <keyword>capitalize</keyword>
       <keyword>center-left</keyword>