OPT: batch_processing: added pause after opening FSL
OPT: batch_processing: added pause after opening FSL

Former-commit-id: 2e5119dddb90b8625e808cf952eac3bfbce39c79
Former-commit-id: fe414f8f73a55cbaec562e758653cfdffb87077d
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox