Minor fix to #426 to still reproduce the issue (need equivalent visibility)

Author: cowtowncoder

src/test/java/com/fasterxml/jackson/failing/TestUnknownProperty426.java

@@ -15,7 +15,7 @@ static class User {
         public String firstName;
         Integer userId; 
 
-        void setUserId(CharSequence id) {
+        public void setUserId(CharSequence id) {
             // 21-Dec-2015, tatu: With a fix in 2.7, use of String would not
             //   trigger the problem, so use CharSequence...
             setUserId(new Integer(id.toString()));