Do not bail too early when trapping properties in acs scriptlet

Related feedback:
- uBlockOrigin/uBlock-issues#2130 (comment)

assets/resources/scriptlets.js

@@ -253,6 +253,7 @@ function abortCurrentScriptCore(
     for (;;) {
         prop = chain.shift();
         if ( chain.length === 0 ) { break; }
+        if ( prop in owner === false ) { break; }
         owner = owner[prop];
         if ( owner instanceof Object === false ) { return; }
     }