500.html in washout_builder-1.7.5

- old
+ new

@@ -1,6 +1,6 @@
 <!DOCTYPE html>
-<html>
+<html lang="en">
 <head>
   <title>We're sorry, but something went wrong (500)</title>
   <style type="text/css">
     body { background-color: #fff; color: #666; text-align: center; font-family: arial, sans-serif; }
     div.dialog {