Crash attempting to write reindex log file

[ndevenish]

Due to change in 12d7eae the captured stdout stream lines are now a str, not a bytes object. A previous attempt to fix this was made in 6576167, but that removed the functionality where a log file is written for commands that don't otherwise write on.

Traceback (most recent call last): 
 File "/home/luiso/ccp4-20211009/lib/python3.7/site-packages/dui/m_idials_gui
.py", line 128, in run 
   self.ref_to_controler.run(command=self.cmd_to_run, ref_to_class=self) 
 File "/home/luiso/ccp4-20211009/lib/python3.7/site-packages/dui/m_idials.py"
, line 202, in run 
   self.current_node(cmd_lst, ref_to_class) 
 File "/home/luiso/ccp4-20211009/lib/python3.7/site-packages/dui/m_idials.py"
, line 111, in __call__ 
   b"\n".join(self.dials_command.tmp_std_all) + b"\n" 
TypeError: sequence item 0: expected a bytes-like object, str found