Change description for the field used to upload images

The field used in the image node to upload the image uses 'Click "Browse..." to select an image to upload.'.
This description should be changed because:

• 'Browse...' could not be the text the user sees in his browser; the language Drupal uses is different from the language used by the browser the user is using;
• in Safari, such button doesn't appear at all, even when the browser is localized in English.

That could confuse the user, which would not understand what to do (I know, he should be really a beginner, but still...).