A workaround is to `cp /etc/urlview/system.urlview ~/.urlview` and then replace REGEXP with
REGEXP (((http|https|ftp|gopher)|mailto):(//)?[^ <>"\t]*|(www|ftp)[0-9]?\.[-a-z0-9.]+)[^ .,;\t\n\r<">\):]?[^, <>"\t]*[^ .,;\t\n\r<">:] (i.e. erasing that last “\)”). I would send a patch but am not a regexp expert — nor I understood where upstream repository is —, so I am not 100% sure the modification is sensible.