'Error' in deployement blocks everything

[rienafairefr]

When starting an experiment and the initial firmware flash doesn't work (maybe wrong elf selected, whatever), then it's totally impossible to flash another firmware, the node is blocked in Error mode. If the error is a "permanent" failure of the node (no connection possible, etc.), I can understand greying out the actions. But for a recoverable failure (wrong selected firmware, for example), the options shouldn't be greyed out