I'm no Linux guru but I can work stuff out sometimes...lol.
You shouldn't have to change anything in that script from the guide, just copy and paste it in. I assume you are running OMV as the root user when installing seafile.
The above looks like a pearl setting issues. A little bit of googling I found this that might help: http://ubuntuforums.org/showthread.php?t=1346581 . You could also check you installed the python packages correctly.
Is the problem you are having related to the start up part of the guide ## Part Three: Start Seafile at System Bootup ##. Are you able to run Seafile manually?