Clearing description on category "other" event produces duplicate category tag

[MatthewGidcomb]

Reproduction steps:

• Select the "Other" category and enter some text in the "What type of event are you putting on?" input field.
• Clear the input field.
• Enter new text into the field.
• Use the Vue dev tools to inspect the Submission form's state or submit the event and inspect the resulting event.
• The tags column should contain category:other:<the text you entered in the field> but instead it contains that plus an additional category:other tag.

[MatthewGidcomb]

Should be fixed by #450, which completely reworked how category is stored such that it shouldn't be possible to duplicate the info. We'll check before closing for good.

[MatthewGidcomb]

Still need to follow up on confirming this is fixed.