What is on your mind -> What's on your mind (#7938)

app/javascript/mastodon/locales/en.json

@@ -65,7 +65,7 @@
   "compose_form.hashtag_warning": "This toot won't be listed under any hashtag as it is unlisted. Only public toots can be searched by hashtag.",
   "compose_form.lock_disclaimer": "Your account is not {locked}. Anyone can follow you to view your follower-only posts.",
   "compose_form.lock_disclaimer.lock": "locked",
-  "compose_form.placeholder": "What is on your mind?",
+  "compose_form.placeholder": "What's on your mind?",
   "compose_form.publish": "Toot",
   "compose_form.publish_loud": "{publish}!",
   "compose_form.sensitive.marked": "Media is marked as sensitive",