message: Fix typo in undeline snippet
diff: },
  "underline": {
  "prefix": "FUL",
  - "body": "\\upperline{${1:${TM_SELECTED_TEXT:text}}}",
  + "body": "\\underline{${1:${TM_SELECTED_TEXT:text}}}",
  "description": "Underline text"
  },
  "uppercase": {
  