remove unnecessary printouts

src/GUI/ChatScreen.java

src/client/ChatUpdate.java

src/client/Client.java

src/client/ClientUpdate.java

src/client/DrawingUpdate.java

src/client/EncryptionUpdate.java

src/remote/EncryptDecrypt.java

src/server/ChatController.java

src/server/ClientController.java

src/server/DrawingController.java

src/server/MySharedKey.java

src/server/Server.java