Remove missed references to delete mapping API

See #10231

docs/reference/migration/migrate_1_0.asciidoc

@@ -143,7 +143,6 @@ In the future we will also provide plural versions to allow putting multiple map
 
 See <<indices-put-mapping,`put-mapping`>>, <<indices-get-mapping,`get-
 mapping`>>, <<indices-get-field-mapping,`get-field-mapping`>>,
-<<indices-delete-mapping,`delete-mapping`>>,
 <<indices-update-settings,`update-settings`>>, <<indices-get-settings,`get-settings`>>,
 <<indices-warmers,`warmers`>>, and <<indices-aliases,`aliases`>> for more details.
 

rest-api-spec/api/indices.delete_mapping.json

@@ -1,29 +0,0 @@
-{
-  "indices.delete_mapping": {
-    "documentation": "http://www.elastic.co/guide/en/elasticsearch/reference/master/indices-delete-mapping.html",
-    "methods": ["DELETE"],
-    "url": {
-      "path": "/{index}/{type}/_mapping",
-      "paths": ["/{index}/{type}/_mapping", "/{index}/{type}", "/{index}/_mapping/{type}", "/{index}/{type}/_mappings", "/{index}/_mappings/{type}"],
-      "parts": {
-        "index": {
-          "type" : "list",
-          "required" : true,
-          "description" : "A comma-separated list of index names (supports wildcards); use `_all` for all indices"
-        },
-        "type": {
-          "type" : "list",
-          "required" : true,
-          "description" : "A comma-separated list of document types to delete (supports wildcards); use `_all` to delete all document types in the specified indices."
-        }
-      },
-      "params": {
-        "master_timeout": {
-          "type" : "time",
-          "description" : "Specify timeout for connection to master"
-        }
-      }
-    },
-    "body": null
-  }
-}