Merge with 4.11.8

src/Umbraco.Web.UI/web.Template.config

@@ -93,7 +93,7 @@
     <globalization requestEncoding="UTF-8" responseEncoding="UTF-8" />
     <xhtmlConformance mode="Strict" />
 
-    <httpRuntime requestValidationMode="2.0" />
+    <httpRuntime requestValidationMode="2.0" enableVersionHeader="false" />
 
     <pages enableEventValidation="false">
       <!-- ASPNETAJAX -->
@@ -232,6 +232,14 @@
       <remove fileExtension=".air" />
       <mimeMap fileExtension=".air" mimeType="application/vnd.adobe.air-application-installer-package+zip" />
     </staticContent>
+
+    <!-- Ensure the powered by header is not returned -->
+    <httpProtocol>
+      <customHeaders>
+        <remove name="X-Powered-By"/>
+      </customHeaders>
+    </httpProtocol>
+    
   </system.webServer>
 
   <system.codedom>