Rename "crop" to "change preview" (mastodon#9616)

Author: Gargron

app/javascript/mastodon/locales/en.json

@@ -341,7 +341,7 @@
   "upload_area.title": "Drag & drop to upload",
   "upload_button.label": "Add media (JPEG, PNG, GIF, WebM, MP4, MOV)",
   "upload_form.description": "Describe for the visually impaired",
-  "upload_form.focus": "Crop",
+  "upload_form.focus": "Change preview",
   "upload_form.undo": "Delete",
   "upload_progress.label": "Uploading...",
   "video.close": "Close video",