Update src/tree.js

Co-authored-by: Neil Fernandez <neil.fernandez@oracle.com>

Author: vadim-tropashko

src/tree.js

@@ -1169,7 +1169,7 @@ let tree = (function(){
             postfix =  'and\n';   
             if( 0 < ret.indexOf(postfix) && ret.indexOf(postfix) == ret.length-postfix.length )
                 ret = ret.substring(0, ret.length-postfix.length).trim(); 
-            if( !ret.endsWith('/n') )
+            if( !ret.endsWith('\n') )
                 ret += '\n';         
             ret += '/\n'; 
             return ret.toLowerCase();