GIFs not looping

[gorczyca]

Running the elevator example (with slightly changed encoding for reasons explained in #114) that is:

instance:

#const floors=5.
floor(1..floors).

at((floors+1)/2,10). 
called(floors,10).
called(1,10).

encoding:

#const horizon=25.
time(10..horizon).
...

with the provided command:
clingo examples/elevator/encoding.lp examples/elevator/viz.lp examples/elevator/instance.lp --outf=2 | clingraph --out=animate --select-model=0 --dir='out/elevator' --fps=1 --sort=asc-int

produces a non-looping GIF, unlike the one shown in the example: