No need to worry. We don't exclude websites over such small issues.
Depending on the situation this is how you should act.
Situation A: the old url is listed in DMOZ
Go to the category where your site is listed, click on "update listing" an fill in the form replace the url with the new one and tell us what happened.
If the old url is still active it is essential for us (and any of your visitors) that the old website inlcudes a link to the new url
Situation B: the old url is not listed in DMOZ
Suggest the new url and add an explanation that it overwrites your previous suggestion of old.url
The explanation could be added to the description between [ ]
like "This is my description. [this is new url for previous suggested abc.tld]"