errors leave task running #2

in some cases task errors will be caught by the interface properly but still prevent new tasks from running. in these cases the message "Already running task!" will be presented in the report when a new experiment is started.

on windows 10 steps to reproduce:

start a new manual cursor task
create a new sequence
set one of the sequence parameters to something nonsense (e.g. nblocks to 'q')
press start
when the task fails, fix the sequence and press start again

aolabNeuro / brain-python-interface

errors leave task running #2 #3