fix(conf): add crl related config default values in conf

etc/emqx.conf

@@ -1566,14 +1566,14 @@ listener.ssl.external.cacertfile = {{ platform_etc_dir }}/certs/cacert.pem
 ##
 ## Value: Duration
 ## Default: 15 s
-## crl_cache_http_timeout = 15s
+crl_cache_http_timeout = 15s
 
 ## The period to refresh the CRLs from the servers.  This is global
 ## for all URLs and listeners.
 ##
 ## Value: Duration
 ## Default: 15 m
-## crl_cache_refresh_interval = 15m
+crl_cache_refresh_interval = 15m
 
 ## The Ephemeral Diffie-Helman key exchange is a very effective way of
 ## ensuring Forward Secrecy by exchanging a set of keys that never hit

priv/emqx.schema

@@ -1698,7 +1698,7 @@ end}.
 ]}.
 
 {mapping, "listener.ssl.$name.ocsp_refresh_http_timeout", "emqx.listeners", [
-  {default, "15000ms"},
+  {default, "15s"},
   {datatype, {duration, ms}}
 ]}.