Remove invalid/unnecessary shebang lines

mpcdf_branch.py

mpcdf_enable_repositories.py

mpcdf_push.py

mpcdf_remove.py

mpcdf_set_as_branch.py

mpcdf_setup_home_project.py

mpcdf_setup_software_project.py

mpcdf_setup_subproject.py

mpcdf_sync_projects.py