Category selection broken for "Reply as new topic"

[supermathie (Michael Brown)]

To reproduce:

1. Select a bit of text and Quote:

   

2. Choose to Reply as linked topic

   

3. Change the category from the original one (note that without searching, only the current category is listed):

   

4. To something new:

   

5. The category now shows as uncategorized but in actuality the category (bug in this case) is actually selected and will be used on the new topic:

   

[joffreyjaffeux]

Will be fixed by

https://github.com/discourse/discourse/pull/7002