Loading solo with pinocchio 2.1.7

leads to the following error:

python: /opt/openrobots/include/pinocchio/parsers/srdf.hxx:201: bool pinocchio::srdf::loadRotorParameters(pinocchio::ModelTpl<Scalar, Options, JointCollectionTpl>&, const string&, bool) [with Scalar = double; int Options = 0; JointCollectionTpl = pinocchio::JointCollectionDefaultTpl; std::__cxx11::string = std::__cxx11::basic_string<char>]: Assertion `false && "no rotor params found in the srdf file"' failed.

This issue was initially reported by @sduminy