[SC-169] Fix channel picking in ex_connectivity
[SC-169] Fix channel picking in ex_connectivity

mne-tools/mne-cpp,LorenzE/mne-cpp,mne-tools/mne-cpp,mne-tools/mne-cpp,chdinh/mne-cpp,LorenzE/mne-cpp,LorenzE/mne-cpp,mne-tools/mne-cpp,chdinh/mne-cpp,mne-tools/mne-cpp,mne-tools/mne-cpp,chdinh/mne-cpp,chdinh/mne-cpp,LorenzE/mne-cpp,chdinh/mne-cpp,chdinh/mne-cpp