SPARQL: Fix variable binding with subqueries
SPARQL: Fix variable binding with subqueries

hoheinzollern/tracker,hoheinzollern/tracker,outofbits/tracker,outofbits/tracker,hoheinzollern/tracker,hoheinzollern/tracker,hoheinzollern/tracker,hoheinzollern/tracker,outofbits/tracker,outofbits/tracker,hoheinzollern/tracker,outofbits/tracker,outofbits/tracker,outofbits/tracker