[bdsim BUG] When block is completely discrete, no integrator reference should be used

[mandicLuka]

bdsim version 1.1.2
Describe the bug
Error:

File ".../lib/python3.10/site-packages/bdsim/run_sim.py", line 918, in run_interval
out = b.output(integrator.t, b.inputs, b._x)[p.port]
UnboundLocalError: local variable 'integrator' referenced before assignment

To Reproduce
Any block diagram with only discrete blocks

Expected behavior
Simulation runs smoothly

Operating environment (please complete the following information):

• OS: Ubuntu 22.04

Suggestion:

instead

out = b.output(integrator.t, b.inputs, b._x)[p.port]

use

out = b.output(t, b.inputs, b._x)[p.port]

as integrator is not defined here