`NoJump` transformation fails in a non intuitive way when applied outside of the first frame

[IAlibay]

Expected behavior

NoJump should fail when applied outside of the first frame (at least it makes sense to me), but it should do so in a way that is a bit more informative.

Actual behavior

TypeError: unsupported operand type(s) for -: 'float' and 'NoneType'

Code to reproduce the behavior

import MDAnalysis as mda
from MDAnalysis.tests.datafiles import GRO, XTC
from MDAnalysis.transformations.nojump import NoJump

u = mda.Universe(GRO, XTC)
u.trajectory[-1]

u.trajectory.add_transformations(NoJump())

[TejasNangru]

Please assign me this issue.

[orbeckst]

@TejasNangru you're very welcome to contribute a solution, please open a PR that references this issue. We don't normally assign open issues in advance. Just seeing the linked PR will direct reviewers to your work.