MIA crashes when we click on `-` button 3 times

Procedure to reproduce the bug:

launch MIA
go to 'Pipeline Manager'
click on - button 3 times (button with the symbol '-' in red , that is on the line 'Tags to visualize')
MIA crashes

Error message:

Exception hooking in progress ...

Clean up     before closing mia done ...

Traceback (most recent call last):
File "/home/omontigon/Apps/casa_distro/populse_mia/python/populse_mia/user_interface/pipeline_manager/iteration_table.py", line 255, in remove_tag
    push_button = self.push_buttons[-1]
IndexError: list index out of range

populse / populse_mia

MIA crashes when we click on `-` button 3 times #213