If your using the quoted method, then it makes a backup of the original html file. If you have yet to make any changes, then you might have affected something else Ovi Maps depends on like the plugin or microB.

these lines make a backup of the original html files and then zip them up (I think... I never tried them but it seems like it). To go back you'll need to do the opposite, so

mv index.html.nokia index.html

Maybe check with someone who has more experience with linux before trying. Alternatively if you use something like winscp you may just view the folder and edit it that way.