Removed trailing colon

[Grzegorz Adam Hankiewicz]

* en/book/ch09.xml: Removed trailing colon.

Index: en/book/ch09.xml
===================================================================
--- en/book/ch09.xml    (revision 1317)
+++ en/book/ch09.xml    (working copy)
@@ -903,7 +903,7 @@
         </refsect1>
 
         <refsect1>
-          <title>Switches:</title>
+          <title>Switches</title>
 
           <screen>
 --diff3-cmd CMD