Update Function object, NFE article

Fix minor typo in Function object, NFE article.

1-js/06-advanced-functions/06-function-object/article.md

@@ -326,7 +326,7 @@ welcome(); // Hello, Guest (nested call works)
 
 Now it works, because the name `"func"` is function-local. It is not taken from outside (and not visible there). The specification guarantees that it will always reference the current function.
 
-The outer code still has its variable `sayHi` or `welcome`. And `func` is an "internal function name", the way for the function to can call itself reliably.
+The outer code still has its variable `sayHi` or `welcome`. And `func` is an "internal function name", the way for the function to call itself reliably.
 
 ```smart header="There's no such thing for Function Declaration"
 The "internal name" feature described here is only available for Function Expressions, not for Function Declarations. For Function Declarations, there is no syntax for adding an "internal" name.