added vault configure menu wrong input message

src/main/java/Vault.java

@@ -39,6 +39,8 @@ public class Vault implements VaultInterface {
 
         if (input.equals("e")) {
             config = false;
+        }else if (!input.equals("l")|!input.equals("l")|!input.equals("l")) {
+            println("Please enter valid key.");
         }
 
     }

src/test/java/VaultTest.java

@@ -79,6 +79,16 @@ public class VaultTest {
         assertTrue(outputStream.toString().startsWith("Configure:"));
     }
 
+    @Test
+    void configureMenuWrongInputMessage() {
+        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+        vlt.inputS = new ByteArrayInputStream("__\n".getBytes(StandardCharsets.UTF_8));
+        vlt.outputS = outputStream;
+        vlt.configure();
+        assertTrue(outputStream.toString().contains("Please"));
+    }
+
+
     @Test
     void openSetPWLength() {
         ByteArrayOutputStream outputStream = new ByteArrayOutputStream();