[Minor] config: don't lie about antivirus whitelist

conf/modules.d/antivirus.conf

@@ -48,7 +48,7 @@ antivirus {
       # symbol_name = "pattern";
       #CLAM_PROTOCOL_ERROR = '^unhandled response';
     #}
-    # `whitelist` points to a map of IP addresses. Mail from these addresses is not scanned.
+    # `whitelist` points to a map of signature names. Hits on these signatures are ignored.
     #whitelist = "/etc/rspamd/antivirus.wl";
   #}