[ldapfeed] re-enable ldap tests for python 3.7 This was disabled because ldap3<2 wasn't compatible with python 3.7 While I'm here, drop unseless newline.

version=3
opts=uversionmangle=s/(rc|a|b|c)/~$1/ \
https://pypi.debian.net/cubicweb/cubicweb-(.+)\.(?:zip|tgz|tbz|txz|(?:tar\.(?:gz|bz2|xz)))