Viewing of requests crashes

[SamJoan]

The request crashes under certain conditions.

Steps to repro

1. Add to scope a folder that has many sub requests. Like http://192.168.153.136/shelling/test_cases/. Make all requests Fuzzed
2. Change it to a specific URL: http://192.168.153.136/shelling/test_cases/no_white_chars_start_alphanum.php
3. Change it back to http://192.168.153.136/shelling/test_cases/

It crashes and requests lose Fuzzed State.

Error stack trace is:

[ERROR 2020-02-19 11:17:00,898]: Exception in thread
Traceback (most recent call last):
  File "C:\Users\pedro\code\benteveo-toolbox\ui.py", line 329, in run
    self.method(*self.args, **self.kwargs)
  File "C:\Users\pedro\code\benteveo-toolbox\ui.py", line 423, in refreshButtonClicked
    self.state.endpointTableModel.add(request)
  File "C:\Users\pedro\code\benteveo-toolbox\tables.py", line 223, in add
    self.fireTableRowsInserted(added_at_index - 1, added_at_index - 1)
  File "C:\Users\pedro\code\benteveo-toolbox\tables.py", line 265, in getValueAt
    endpointModel = self.getEndpoint(rowIndex)
  File "C:\Users\pedro\code\benteveo-toolbox\tables.py", line 187, in getEndpoint
    return self.endpoints.items()[rowIndex][1]
IndexError: index out of range: 1
Traceback (most recent call last):
  File "C:\Users\pedro\code\benteveo-toolbox\ui.py", line 329, in run
    self.method(*self.args, **self.kwargs)
  File "C:\Users\pedro\code\benteveo-toolbox\ui.py", line 423, in refreshButtonClicked
    self.state.endpointTableModel.add(request)
  File "C:\Users\pedro\code\benteveo-toolbox\tables.py", line 223, in add
    self.fireTableRowsInserted(added_at_index - 1, added_at_index - 1)
  File "C:\Users\pedro\code\benteveo-toolbox\tables.py", line 265, in getValueAt
    endpointModel = self.getEndpoint(rowIndex)
  File "C:\Users\pedro\code\benteveo-toolbox\tables.py", line 187, in getEndpoint
    return self.endpoints.items()[rowIndex][1]
IndexError: index out of range: 1