mark submit-entity-body.html as needing a long timeout.

After discussion with jdm.
servo · bors-servo · Nov 14, 2016 · Oct 7, 2016 · Nov 14, 2016 · Nov 14, 2016
commit 58bd039b5095346f715493431a1c60389c897141
diff --git a/tests/wpt/metadata/MANIFEST.json b/tests/wpt/metadata/MANIFEST.json

             "url": "/cssom-view/MediaQueryList-with-empty-string.html"
           }
         ],
+        "html/semantics/forms/form-submission-0/submit-entity-body.html": [
+          {
+            "path": "html/semantics/forms/form-submission-0/submit-entity-body.html",
+            "timeout": "long",
+            "url": "/html/semantics/forms/form-submission-0/submit-entity-body.html"
+          }
+        ],
         "html/semantics/forms/the-form-element/form-action-url.html": [
           {
             "path": "html/semantics/forms/the-form-element/form-action-url.html",
diff --git a/tests/wpt/web-platform-tests/html/semantics/forms/form-submission-0/submit-entity-body.html b/tests/wpt/web-platform-tests/html/semantics/forms/form-submission-0/submit-entity-body.html
@@ -1,5 +1,6 @@
 <!DOCTYPE html>
 <meta charset="utf-8">
+<meta name="timeout" content="long">
 <script src="/resources/testharness.js"></script>
 <script src="/resources/testharnessreport.js"></script>
 <script>