BUG: EDF stim resampling when NaN/inf are present

Describe the bug

I cannot plot the data again after applying filtering.

Steps to reproduce

	data_highpass = data.copy().filter(l_freq=0.5, h_freq=None)
	
	data.plot(n_channels=61, scalings="auto") # this works as expected
	plt.show()

	data_highpass.plot(n_channels=61, scalings="auto") # here I get the error
	plt.show()

Expected results

It should be able to plot data after filtering

Actual results

ValueError: cannot convert float NaN to integer

Additional information

Platform: Linux-5.3.0-45-generic-x86_64-with-glibc2.10
Python: 3.8.1 (default, Jan 8 2020, 22:29:32) [GCC 7.3.0]
Executable: /home/andrea/anaconda3/envs/bci_competition/bin/python
CPU: x86_64: 8 cores
Memory: 7.6 GB

mne: 0.19.2
numpy: 1.18.1 {blas=mkl_rt, lapack=mkl_rt}
scipy: 1.4.1
matplotlib: 3.2.0 {backend=TkAgg}

sklearn: 0.22.2.post1
numba: Not found
nibabel: Not found
cupy: Not found
pandas: 1.0.1
dipy: Not found
mayavi: Not found
pyvista: Not found
vtk: Not found

Start by reproducing the filtering and plotting sequence from the issue with the reported MNE, NumPy, SciPy, and Matplotlib versions, and inspect where the NaN-to-integer ValueError is raised. Trace the EDF stimulus resampling and plotting path; done means filtered data containing NaN or inf can be plotted without this error, with a regression test covering the reproduction.