Verified curtin package in xenial-proposed fixes the formatting issue in /etc/network/interfaces when adding static routes through MaaS gui.
dpkg -l | grep curtin
ii curtin-common 0.1.0~bzr460-0ubuntu1~16.04.1 all Library and tools for curtin installer
ii python3-curtin 0.1.0~bzr460-0ubuntu1~16.04.1 all Library and tools for curtin installer
Verified curtin package in xenial-proposed fixes the formatting issue in /etc/network/ interfaces when adding static routes through MaaS gui.
dpkg -l | grep curtin 0ubuntu1~ 16.04.1 all Library and tools for curtin installer 0ubuntu1~ 16.04.1 all Library and tools for curtin installer
ii curtin-common 0.1.0~bzr460-
ii python3-curtin 0.1.0~bzr460-