Fix attribute form choice type error.

| Q	                       | A     |
|--------------------------|------ |
| Bug Fix?        	| yes     |
| New Feature?	| n     |
| BC Breaks?	       | n     |
| Deprecations?	| n     |
| Tests Pass?	       | n     |
| Fixed Tickets	       | #249 #417 #651 #743 #1845 #2006 |
| License	               | MIT |
| Doc PR                  |        |

This's still not perfect solution but can fix many issues for now.
Ah right... why not using native functions? :smile: 
```php
$choices = array_combine($data['choices'], $data['choices']);