Issue #994. Add a 413 handler.

webcompat/views.py

@@ -41,6 +41,7 @@
               401: 'Unauthorized. Please log in.',
               403: 'Forbidden. Maybe that looking at private stuff?',
               404: 'Not Found. Lost in Punk Cat Space',
+              413: 'The image is too big!',
               429: 'Cool your jets! Please wait {0} seconds before making '
                    'another search.',
               500: 'Internal Server Error'}
@@ -299,14 +300,13 @@ def cssfixme():
 @app.errorhandler(401)
 @app.errorhandler(403)
 @app.errorhandler(404)
+@app.errorhandler(413)
 @app.errorhandler(500)
 def custom_error_handler(err):
     if api_call(request):
         return api_message(err.code)
-    return render_template(
-        'error.html',
-        error_code=err.code,
-        error_message=ERROR_DICT[err.code]), err.code
+    return render_template('error.html', error_code=err.code,
+                           error_message=ERROR_DICT[err.code]), err.code
 
 
 def api_call(request):