replace lambda with method reference while streaming managers
diff --git a/jspwiki-main/src/main/java/org/apache/wiki/WikiEngine.java b/jspwiki-main/src/main/java/org/apache/wiki/WikiEngine.java
index f6856b0..223817c 100644
--- a/jspwiki-main/src/main/java/org/apache/wiki/WikiEngine.java
+++ b/jspwiki-main/src/main/java/org/apache/wiki/WikiEngine.java
@@ -545,7 +545,7 @@
     public < T > List< T > getManagers( final Class< T > manager ) {
         return ( List< T > )managers.entrySet().stream()
                                     .filter( e -> manager.isAssignableFrom( e.getKey() ) )
-                                    .map( e -> e.getValue() )
+                                    .map( Map.Entry::getValue )
                                     .collect( Collectors.toList() );
     }