Editable column values are failing due to execption

[djpnewton]

https://github.com/flask-admin/flask-admin/blob/b22e2745568c5e14d85abfff40fc86ba04ae3656/flask_admin/static/admin/js/form.js#L496-L497

Editable column values are failing as the above code attempts to concat two arrays but JS seems to convert that into a string resulting in the following execption:

jQuery.Deferred exception: cannot use 'in' operator to search for "length" in "[object Object]" p@https://localhost/admin/static/vendor/jquery.min.js?v=3.5.1:2:1065
each@https://localhost/admin/static/vendor/jquery.min.js?v=3.5.1:2:2938
display@https://localhost/admin/static/admin/js/form.js?v=1.0.1:500:31
render@https://localhost/admin/static/vendor/x-editable/js/bootstrap3-editable.min.js?v=1.5.1.1:5:16079
init@https://localhost/admin/static/vendor/x-editable/js/bootstrap3-editable.min.js?v=1.5.1.1:5:15419
b@https://localhost/admin/static/vendor/x-editable/js/bootstrap3-editable.min.js?v=1.5.1.1:5:14084
a.fn.editable/<@https://localhost/admin/static/vendor/x-editable/js/bootstrap3-editable.min.js?v=1.5.1.1:5:20974
each@https://localhost/admin/static/vendor/jquery.min.js?v=3.5.1:2:2976
each@https://localhost/admin/static/vendor/jquery.min.js?v=3.5.1:2:1454
a.fn.editable@https://localhost/admin/static/vendor/x-editable/js/bootstrap3-editable.min.js?v=1.5.1.1:5:20847
AdminForm/this.applyStyle@https://localhost/admin/static/admin/js/form.js?v=1.0.1:483:21
AdminForm/this.applyGlobalStyles/<@https://localhost/admin/static/admin/js/form.js?v=1.0.1:612:18
each@https://localhost/admin/static/vendor/jquery.min.js?v=3.5.1:2:2976
each@https://localhost/admin/static/vendor/jquery.min.js?v=3.5.1:2:1454
AdminForm/this.applyGlobalStyles@https://localhost/admin/static/admin/js/form.js?v=1.0.1:610:54
@https://localhost/admin/static/admin/js/form.js?v=1.0.1:643:16
e@https://localhost/admin/static/vendor/jquery.min.js?v=3.5.1:2:30005
Deferred/then/l/</t<@https://localhost/admin/static/vendor/jquery.min.js?v=3.5.1:2:30307
setTimeout handler*Deferred/then/l/<@https://localhost/admin/static/vendor/jquery.min.js?v=3.5.1:2:30516
c@https://localhost/admin/static/vendor/jquery.min.js?v=3.5.1:2:28294
fireWith@https://localhost/admin/static/vendor/jquery.min.js?v=3.5.1:2:29039
fire@https://localhost/admin/static/vendor/jquery.min.js?v=3.5.1:2:29075
c@https://localhost/admin/static/vendor/jquery.min.js?v=3.5.1:2:28294
fireWith@https://localhost/admin/static/vendor/jquery.min.js?v=3.5.1:2:29039
ready@https://localhost/admin/static/vendor/jquery.min.js?v=3.5.1:2:32012
B@https://localhost/admin/static/vendor/jquery.min.js?v=3.5.1:2:31791
EventListener.handleEvent*@https://localhost/admin/static/vendor/jquery.min.js?v=3.5.1:2:32160
@https://localhost/admin/static/vendor/jquery.min.js?v=3.5.1:2:220
@https://localhost/admin/static/vendor/jquery.min.js?v=3.5.1:2:225
 undefined jquery.min.js:2:31560