userguide/exceptions: clarify when stats are logged

The stats for exception policies are only logged/ present when any of
the exception policies are enabled (which means any value other than
"auto" or "ignore" in IDS mode, or "ignore" in IPS mode).

This wasn't clearly stated in the docs.

doc/userguide/configuration/exception-policies.rst

@@ -260,7 +260,8 @@ applying the configured behavior for such scenario: *to pass the flow* (``pass_f
 Available Stats
 ~~~~~~~~~~~~~~~
 
-There are stats counters for each supported exception policy scenario:
+There are stats counters for each supported exception policy scenario that will
+be logged when exception policies are enabled:
 
 .. list-table:: **Exception Policy Stats Counters**
    :widths: 50 50
@@ -289,7 +290,7 @@ Stats for application layer errors are available in summarized form or per
 application layer protocol. As the latter is extremely verbose, by default
 Suricata logs only the summary. If any further investigation is needed, it
 is recommended to enable per-app-proto exception policy error counters
-temporarily (for :ref:`stats configuration<suricata_yaml_outputs>`).
+temporarily (for more, read :ref:`stats configuration<suricata_yaml_outputs>`).
 
 
 Command-line Options for Simulating Exceptions