Fix lint issue.

Author: davidlehn

lib/context.js

@@ -1097,11 +1097,11 @@ function _expandIri(activeCtx, value, relativeTo, localCtx, defined, options) {
 
   // A flag that captures whether the iri being expanded is
   // the value for an @type
-  let typeExpansion = false;
+  //let typeExpansion = false;
 
-  if(options !== undefined && options.typeExpansion !== undefined) {
-    typeExpansion = options.typeExpansion;
-  }
+  //if(options !== undefined && options.typeExpansion !== undefined) {
+  //  typeExpansion = options.typeExpansion;
+  //}
 
   if(relativeTo.vocab && '@vocab' in activeCtx) {
     // prepend vocab