Removing null checks as suggested by editor for BAEL-3083

Author: cscib

core-java-modules/core-java-collections-list-2/src/main/java/com/baeldung/findastring/FindAStringInGivenList.java

@@ -47,7 +47,6 @@ public List<String> findUsingStream(String search, List<String> list) {
 
         List<String> matchingElements =
                 list.stream()
-                        .filter(str -> search != null)
                         .filter(str -> str.trim().contains(search))
                         .collect(Collectors.toList());