Only add Caption effect when needed

src/components/Clips.vue

@@ -154,12 +154,14 @@ export default {
           caption.caption_text += `${start_timestamp} --> ${end_timestamp}\n${clip.json.text}\n\n`
         }
       }
-      // Save caption effect
+      // Save caption effect (if any text is needed)
+      if (effect_payload.end > 0) {
         if (is_effect_new) {
           await this.createEffect(effect_payload)
         } else {
           await this.updateEffect(effect_payload)
         }
+      }
 
       // Create export
       let payload = {