[Glitch] Code style improvements in JavaScript

Port fd76955f39 to glitch-soc

* JS-linter: fix trailing comma's

* Configure eslinter to ignore this onchange error.

Signed-off-by: Thibaut Girka <thib@sitedethib.com>

app/javascript/flavours/glitch/features/compose/components/poll_form.js

@@ -143,6 +143,7 @@ class PollForm extends ImmutablePureComponent {
             <option value='true'>{intl.formatMessage(messages.multiple_choices)}</option>
           </select>
 
+          {/* eslint-disable-next-line jsx-a11y/no-onchange */}
           <select value={expiresIn} onChange={this.handleSelectDuration}>
             <option value={300}>{intl.formatMessage(messages.minutes, { number: 5 })}</option>
             <option value={1800}>{intl.formatMessage(messages.minutes, { number: 30 })}</option>