Fix for CSR related tests in certificate bucket

Changes:
    - keybit_length is suppose to have interger value. So now setting
      keybit_length variable to an interger value of 2048.

Tested:
    - Ran below test cases from sandbox successfully
      Verify_CSR_Generation_For_Server_Certificate
      Verify_CSR_Generation_For_Client_Certificate

Change-Id: I3e797bb53dbfacd856d2fc050f802a57b8a45e40
Signed-off-by: Rahul Maheshwari <rahulmaheshwari@in.ibm.com>
diff --git a/redfish/managers/test_certificate.robot b/redfish/managers/test_certificate.robot
index 71f8ac5..e7e70d1 100644
--- a/redfish/managers/test_certificate.robot
+++ b/redfish/managers/test_certificate.robot
@@ -18,7 +18,7 @@
 
 ${invalid_value}  abc
 ${ROOT_CA_FILE_PATH}  /etc/ssl/certs/authority/*
-${keybit_length}  2048
+${keybit_length}  ${2048}
 
 ** Test Cases **