Remove non-Web XMLHTTPRequest page (mdn#12733)

This is linked from one and only one page
and requires long-unsupported, Firefox-only APIs.

files/en-us/_redirects.txt

@@ -4009,7 +4009,7 @@
 /en-US/docs/HTTP_Transaction_Model	/en-US/docs/Web/HTTP
 /en-US/docs/HTTP_access_control	/en-US/docs/Web/HTTP/CORS
 /en-US/docs/How_to_Turn_Off_Form_Autocompletion	/en-US/docs/Web/Security/Securing_your_site/Turning_off_form_autocompletion
-/en-US/docs/How_to_check_the_security_state_of_an_XMLHTTPRequest_over_SSL	/en-US/docs/Web/API/XMLHttpRequest/How_to_check_the_security_state_of_an_XMLHTTPRequest_over_SSL
+/en-US/docs/How_to_check_the_security_state_of_an_XMLHTTPRequest_over_SSL	/en-US/docs/Web/API/XMLHttpRequest
 /en-US/docs/How_to_create_a_DOM_tree	/en-US/docs/Web/API/Document_object_model/How_to_create_a_DOM_tree
 /en-US/docs/How_to_start_contributions_to_Mozilla	/en-US/docs/MDN/Contribute/Getting_started
 /en-US/docs/ICC_color_correction_in_Firefox	/en-US/docs/Mozilla/Firefox/Releases/3.5/ICC_color_correction_in_Firefox
@@ -9113,7 +9113,8 @@
 /en-US/docs/Web/API/XMLDocument.load	/en-US/docs/Web/API/XMLDocument/load
 /en-US/docs/Web/API/XMLHttpRequest/FormData	/en-US/docs/Web/API/FormData
 /en-US/docs/Web/API/XMLHttpRequest/FormData/Using_FormData_Objects	/en-US/docs/Web/API/FormData/Using_FormData_Objects
-/en-US/docs/Web/API/XMLHttpRequest/How_to_check_the_secruity_state_of_an_XMLHTTPRequest_over_SSL	/en-US/docs/Web/API/XMLHttpRequest/How_to_check_the_security_state_of_an_XMLHTTPRequest_over_SSL
+/en-US/docs/Web/API/XMLHttpRequest/How_to_check_the_secruity_state_of_an_XMLHTTPRequest_over_SSL	/en-US/docs/Web/API/XMLHttpRequest
+/en-US/docs/Web/API/XMLHttpRequest/How_to_check_the_security_state_of_an_XMLHTTPRequest_over_SSL	/en-US/docs/Web/API/XMLHttpRequest
 /en-US/docs/Web/API/XMLHttpRequest/XMLHttpRequest.response	/en-US/docs/Web/API/XMLHttpRequest/response
 /en-US/docs/Web/API/XMLHttpRequest/responseresponseText	/en-US/docs/Web/API/XMLHttpRequest/responseText
 /en-US/docs/Web/API/XMLHttpRequestResponseType	/en-US/docs/Web/API/XMLHttpRequest/responseType

files/en-us/_wikihistory.json

@@ -90173,16 +90173,6 @@
       "Hsivonen"
     ]
   },
-  "Web/API/XMLHttpRequest/How_to_check_the_security_state_of_an_XMLHTTPRequest_over_SSL": {
-    "modified": "2019-03-23T23:58:55.741Z",
-    "contributors": [
-      "maulikkothari92",
-      "Jeremie",
-      "teoli",
-      "briansmith2",
-      "vladimir.dzhuvinov"
-    ]
-  },
   "Web/API/XMLHttpRequest/Sending_and_Receiving_Binary_Data": {
     "modified": "2019-10-01T12:14:45.461Z",
     "contributors": [

files/en-us/web/api/xmlhttprequest/using_xmlhttprequest/index.md

@@ -929,15 +929,13 @@ Setting `overrideMimeType` does not work from a {{domxref("Worker")}}. See
 ## See also
 
 1. [MDN AJAX introduction](/en-US/docs/Web/Guide/AJAX/Getting_Started)
-2. [HTML in
+1. [HTML in
     XMLHttpRequest](/en-US/docs/Web/API/XMLHttpRequest/HTML_in_XMLHttpRequest)
-3. [HTTP access control](/en-US/docs/Web/HTTP/CORS)
-4. [How
-    to check the security state of an XMLHTTPRequest over SSL](/en-US/docs/Web/API/XMLHttpRequest/How_to_check_the_security_state_of_an_XMLHTTPRequest_over_SSL)
-5. [XMLHttpRequest -
+1. [HTTP access control](/en-US/docs/Web/HTTP/CORS)
+1. [XMLHttpRequest -
     REST and the Rich User Experience](https://www.peej.co.uk/articles/rich-user-experience.html)
-6. [Microsoft documentation](https://msdn.microsoft.com/library/ms535874)
-7. ["Using the XMLHttpRequest
+1. [Microsoft documentation](https://msdn.microsoft.com/library/ms535874)
+1. ["Using the XMLHttpRequest
     Object" (jibbering.com)](https://jibbering.com/2002/4/httprequest.html)
-8. [The `XMLHttpRequest` object:
+1. [The `XMLHttpRequest` object:
     WHATWG specification](https://xhr.spec.whatwg.org/)