Update interfaces/FileAPI.idl (#15881)

Source: https://github.com/tidoust/reffy-reports/blob/19a80a9/whatwg/idl/FileAPI.idl
Build: https://travis-ci.org/tidoust/reffy-reports/builds/507115788
diff --git a/interfaces/FileAPI.idl b/interfaces/FileAPI.idl
index 789519c..15b2e55 100644
--- a/interfaces/FileAPI.idl
+++ b/interfaces/FileAPI.idl
@@ -75,7 +75,6 @@
   attribute EventHandler onabort;
   attribute EventHandler onerror;
   attribute EventHandler onloadend;
-
 };
 
 [Constructor, Exposed=(DedicatedWorker,SharedWorker)]