Title: #978: Fix another build failure with python 3.8
The parsing of python3-config --ldflags would break if multiple -L
path components were present. This change loops over these paths
until it finds the correct one.
To pull the PR as Git branch:
git remote add ghsssd https://github.com/SSSD/sssd
git fetch ghsssd pull/978/head:pr978
git checkout pr978