[Glitch] Fix media description button being disabled at 420 characters instead of 1500

Port c00ab575b7 to glitch-soc

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

app/javascript/flavours/glitch/features/ui/components/focal_point_modal.js

@@ -226,7 +226,7 @@ class FocalPointModal extends ImmutablePureComponent {
               <CharacterCounter max={1500} text={detecting ? '' : description} />
             </div>
 
-            <Button disabled={!dirty || detecting || length(description) > 420} text={intl.formatMessage(messages.apply)} onClick={this.handleSubmit} />
+            <Button disabled={!dirty || detecting || length(description) > 1500} text={intl.formatMessage(messages.apply)} onClick={this.handleSubmit} />
           </div>
 
           <div className='focal-point-modal__content'>