Add warning for disable_functions and disable_classes (#5429)

Author: iluuu1994

appendices/ini.core.xml

@@ -220,6 +220,12 @@
         This directive must be set in &php.ini;.
         It cannot be set in &httpd.conf;.
        </simpara>
+       <warning>
+        <simpara>
+         This directive can be circumvented and should not be considered a
+         sufficient security measure for shared hosting environments.
+        </simpara>
+       </warning>
       </listitem>
      </varlistentry>
 
@@ -242,6 +248,12 @@
         This directive must be set in &php.ini;.
         It cannot be set in &httpd.conf;.
        </simpara>
+       <warning>
+        <simpara>
+         This directive can be circumvented and should not be considered a
+         sufficient security measure for shared hosting environments.
+        </simpara>
+       </warning>
       </listitem>
      </varlistentry>