fix dataset_validator in case translation_movements_file is None or ''
Fix issue when pass config with translation_movements_file=''
to ProcessConfig
File "/home/payno/dev/tomo/nabu/nabu/resources/processconfig.py", line 68, in __init__
self.build_processing_steps()
File "/home/payno/dev/tomo/nabu/nabu/resources/processconfig.py", line 161, in build_processing_steps
translations = dataset_infos.translations
AttributeError: 'EDFDatasetAnalyzer' object has no attribute 'translations'