Change type to unit for biblScope in commentary.xsg

[jcowey]

In
https://github.com/DCLP/xsugar/blob/master/commentary.xsg#L120-L124

change type to unit

deploy so that it can be tested.

Then change type to unit in
https://github.com/DCLP/idp.data/blob/master/DCLP/62/61916.xml

load in the editor
and see whether it works

[Edelweiss]

xsugar (https://github.com/DCLP/xsugar/tree/issue335)
DCLP/xsugar@e224606
DCLP/xsugar@de1708d

idp.data (https://github.com/DCLP/idp.data/tree/issue335)
DCLP/idp.data@73ebfe0