Fixed typos and added missing 'non'

changelog.html

@@ -71,7 +71,7 @@ Upcoming changes</a>
     NOT_BUILT &amp; other build status are reported inconsistently
     (<a href="https://issues.jenkins-ci.org/browse/JENKINS-11013">issue 11013</a>)
   <li class=bug>
-    Cancelling a parent multi-config build produce deserializable build.xml
+    Canceling a parent multi-config build produces non-deserializable build.xml
     (<a href="https://issues.jenkins-ci.org/browse/JENKINS-10903">issue 10903</a>)
   <li class=bug>
     Label of the master should be editable if cloud is set up.