Fix typo in MDC section

logback-site/src/site/pages/manual/mdc.html

@@ -153,7 +153,7 @@ <h1>Chapter 8: Mapped Diagnostic Context</h1>
 		same key will overwrite older values.  The code then proceeds to
 		configure logback.</p>
 
-    <p>For the sake of conciseness, we have the omitted the code that
+    <p>For the sake of conciseness, we have omitted the code that
     configures logback with the configuration file <a
     href="http://github.com/qos-ch/logback/blob/master/logback-examples/src/main/java/chapters/mdc/simpleMDC.xml">simpleMDC.xml</a>. Here
     is the relevant section from that file.