modified ties look rather bad

Check attached score, created in 2.0.3 (and stripped down to the bone)
The ties out of the volta look OK and as intended in 2.0.3, but become lines into eternity in 27d22e0

Furthermore one of the ties got modified to be below, in 27d22e0 this leads to adebug output:
Debug: tie-volta: xml unknown tag at line 927 col 18: up (...\MuseScore\libmscore\xml.cpp:191, void Ms::XmlReader::unknown())