This was removed in rB0666ece2e2f9 because it is handled differently for
"real" cloth in cloth_solve_collisions(), but hair still needs this
apparently [does its thing in cloth_continuum_step() instead].
And since we have a default 'Quality Steps' setting of 5, it made many
simulations unstable.
Fixes T65038, T59742 (possibly others)
Reviewers: brecht
Maniphest Tasks: T65038, T59742
Differential Revision: https://developer.blender.org/D5681
e52ad1835a