Keey try_remove_component() from throwing a KeyError if the component isn't there

[mfeif]

try_remove_component was actually throwing a KeyError if the entity didn't have the Component as it wasn't guarded by a check or a default value:

return _entities[entity].pop(component_type)

Since the default for a non-extant Component type was to return None, I just added that default value to pop():

return _entities[entity].pop(component_type, None)

[benmoran56]

Thanks @mfeif, not sure how that one got missed!