[WebBundle] Fix for Button 'save' doesn't submit form in order backend edit

| Q             | A
| ------------- | ---
| Bug fix?      | [yes]
| New feature?  | [no]
| BC breaks?    | [no]
| Deprecations? | [no]
| Tests pass?   | [yes]
| Fixed tickets | #1993
| License       | 
| Doc PR        | 


Hi,

Very simple fix to update payment from form edit.