[#2022] fix non-matching quotes and indentation

doc/sphinx/arm/ext-radius.rst

@@ -228,9 +228,9 @@ At the service level, three sections can be configured:
   synchronization process at the startup of an HA node does not trigger a RADIUS
   accounting request, regardless of the value of this flag.
 
-- The ``max-pending-requests'' positive integer value limits the number
-of pending RADIUS requests, the value 0 means no limit. It is supported only
-by the access service, its default is 0 (can change to e.g. 64?).
+- The ``max-pending-requests`` positive integer value limits the number
+  of pending RADIUS requests, the value ``0`` means no limit. It is supported
+  only by the access service, its default is ``0`` (can change to e.g. 64?).
 
 For example, to specify a single access server available on localhost
 that uses ``"xyz123"`` as a secret, and tell Kea to send three additional