Key Error exception during login

Changes:
    - Add exception handling for Key error.
      A session creation error usually causes this
      exception due to invalid and empty credentials.
      Raise a custom exception to handle gracefully
      such an exception during login failure.
    - Add back the removed test case failing in QEMU_CI

Tested:
    - Tested on CI infrastructure, Jenkins, and
      local setup environment

Change-Id: I55d43ae6c62dd88faa700d895683e58c9279e6bc
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/test_lists/QEMU_CI b/test_lists/QEMU_CI
index 9548cde..3c3f838 100644
--- a/test_lists/QEMU_CI
+++ b/test_lists/QEMU_CI
@@ -9,6 +9,7 @@
 --include Redfish_Login_Via_SessionService
 --include Redfish_Login_Using_Invalid_Token
 --include Delete_Redfish_Session_Using_Valid_Login
+--include Redfish_Login_With_Invalid_Credentials
 --include Verify_Update_Service_Enabled
 --include Verify_Redfish_Software_Inventory_Collection
 --include Redfish_Software_Inventory_Status_Check