...a sometimes null object with an error
Python code, file `src/Mod/Part/CompoundTools/Explode.py`
The `explodeCompound` function can be called in a context without assigning the `ViewObject` property, for example from a command line script.
The error that is fixed by this patch.
```
Traceback (most recent call last):
...
File "/opt/freecad/Mod/Part/CompoundTools/Explode.py", line 23, in explodeCompound
cf.ViewObject.DontUnhideOnDelete = True
AttributeError: 'NoneType' object has no attribute 'DontUnhideOnDelete']
```
Patch submitted by marioamb.
Fix#004421https://tracker.freecadweb.org/view.php?id=4421
