add remark regarding closing the javaApp class

src/exercise10/javaApp.java

@@ -13,6 +13,7 @@
  * 	On line 4 the System namespace should be capitalized.
  * 	Also on line 4 the method println accepts a string so the text must be wrapped in ".
  * 	Once more on line 4 a semi colon is missing.
+ *  Finally the class javaApp must be closed 
  * 	
  * 	Fixed version below
  */