Rename private attribute _element to _el

Change-Id: I9c7a31bd6844636737ffa6456562b997f5e370a3
diff --git a/dev/js/src/vc/jsonld.js b/dev/js/src/vc/jsonld.js
index fdee980..06be1e0 100644
--- a/dev/js/src/vc/jsonld.js
+++ b/dev/js/src/vc/jsonld.js
@@ -49,14 +49,14 @@
       const t = this;
       if (t._ops != undefined) {
 	      t._ops._parent = undefined;
-	      if (t._ops._element !== undefined) {
-	        t._ops._element.refTo = undefined;
+	      if (t._ops._el !== undefined) {
+	        t._ops._el.refTo = undefined;
         };
 	      t._ops = undefined;
       };
 
-      if (t._element !== undefined)
-	      t._element = undefined;
+      if (t._el !== undefined)
+	      t._el = undefined;
       
       // In case of a group, destroy all operands
       if (t._operands !== undefined) {