fixed typo in comment

demos/demo.offspot.yaml

@@ -2,7 +2,7 @@
 # this file (in kiwix/operations repository) is the configuration
 # for the hotspot multi demos hosted at http://demo.hotspot.kiwix.org
 # It is periodically fecthed (every 15mn usually) and refreshes the multi-demo
-# should it has changed.
+# should it have changed.
 demos:
   - ident: preppers
     name: Preppers Package