Update locale_en-US.ini

Author: kerwin612

options/locale/locale_en-US.ini

@@ -763,7 +763,7 @@ uploaded_avatar_not_a_image = The uploaded file is not an image.
 uploaded_avatar_is_too_big = The uploaded file size (%d KiB) exceeds the maximum size (%d KiB).
 update_avatar_success = Your avatar has been updated.
 update_user_avatar_success = The user's avatar has been updated.
-cropper_prompt = Note: The saved image format after cropping is unified as JPEG.
+cropper_prompt = Note: The saved image format after cropping is unified as PNG.
 
 change_password = Update Password
 old_password = Current Password