Adds error printing for indexoutofbound case

src/main/java/CredentialRepository.java

@@ -67,7 +67,7 @@ public class CredentialRepository implements CredentialRepositoryInterface{
         }
         catch (IndexOutOfBoundsException outOfBoundsException)
         {
-
+            System.err.println("No Credential with Index" + index + " found");
         }
 
     }
@@ -79,7 +79,7 @@ public class CredentialRepository implements CredentialRepositoryInterface{
         }
         catch (IndexOutOfBoundsException outOfBoundsException)
         {
-
+            System.err.println("No Credential with Index" + index + " found");
         }
     }