Corrected the authentication redirect issue

- Temporary patch, known bug in Plan9

--HG--
branch : dev

src/Orchard.Web/Web.config

@@ -14,8 +14,15 @@
       <section name="pages" type="System.Web.WebPages.Razor.Configuration.RazorPagesSection, System.Web.WebPages.Razor" requirePermission="false" />
     </sectionGroup>
   </configSections>
-  
-  <appSettings/>
+
+  <appSettings>
+    <!--  
+        This is a workaround. There’s a known issue that causes Forms Authentication to always redirect unauthenticated users 
+        to ~/Account/Login, ignoring the forms authentication setting used in Web.config. 
+    -->
+    <add key="autoFormsAuthentication" value="false" />
+  </appSettings>
+
   <system.diagnostics configSource="Config\Diagnostics.config"/>
 
   <system.web.webPages.razor>