Unused variable defined for property-scoped contexts in expansion algorithm

[kasei]

5.1.2 Expansion Algorithm steps 3 says:

If active property has a term definition in active context with a local context, initialize property scoped context to that local context.

However, this seems to be the only occurrence of property scoped context in the entire document. It seems that there's a missing hyphen in the variable name, as property-scoped context does appear later in the algorithm.

[gkellogg]

See comment in #214, it should have been "property-scoped context".

Dupilcate of #214.