[Master] No error message when regex validation is invalid

[condor2]

What version of OpenCart are you reporting this for?
Master

Describe the bug
Add a new Text custom field and write some letters in Validation input (fgfgf) then click save.

No error message it shown.

Console log message error

Unknown: preg_match(): Passing null to parameter #2 ($subject) of type string is deprecated in admin\controller\customer\custom_field.php on line 387

Warning: preg_match(): Delimiter must not be alphanumeric, backslash, or NUL in admin\controller\customer\custom_field.php on line 387{"error":{"validation":"error_validation"}}`

[condor2]

Closed....and Admin warning message where is?

[danielkerr]

@AJenbo im getting a bit worried about some of ur commits now.

[AJenbo]

#12994 (comment)