vscpull.repo.SubversionRepo: Specify --non-interactive
vscpull.repo.SubversionRepo: Specify --non-interactive

This will ensure the command will either timeout or fail without
expecting the user to intervene.

Adapted from CMake/ExternalProject module.
See https://github.com/Kitware/CMake/blob/909d51bece7d343f32a8f59351aad5c396101a2c/Modules/ExternalProject.cmake

tony/vcspull,tony/vcspull