mod_http_cache: add support for http/https formats if enable-file-formats is set to true in http_cache.conf. Don't load mod_httapi if you use this option

src/mod/applications/mod_http_cache/conf/autoload_configs/http_cache.conf.xml

@@ -1,5 +1,7 @@
 <configuration name="http_cache.conf" description="HTTP GET cache">
   <settings>
+    <!-- set to true if you want to enable http:// and https:// formats.  Do not use if mod_httapi is also loaded -->
+    <param name="enable-file-formats" value="false"/>
     <param name="max-urls" value="10000"/>
     <param name="location" value="$${base_dir}/http_cache"/>
     <param name="default-max-age" value="86400"/>
@@ -8,4 +10,3 @@
     <param name="ssl-verifypeer" value="true"/>
   </settings>
 </configuration>
-