"Stupid"-looking breaks in URLs are sometimes tough to avoid. From this post, you can see that the break penalty at a period (along with other symbols) is given by
\UrlBreakPenalty. To avoid breaks at these symbols for a particular set of entries
<key1,key2,...>, you can adapt a previous answer and add the following code to your preamble.
This will reset the break penalty locally from
10000 before printing any entry in the