No option to select the previous encryption certificate when replacing certificate

• Type: Impedibug
• Status: Closed
• Priority: Minor
• Resolution: Discarded
• Affects Version/s: None
• Fix Version/s: None
• Component/s: Application Security > SAML
• Labels: None
• Sprint: Iteration 32, Iteration 33, Iteration 34, Iteration 35, Iteration 36, Iteration 37, Iteration 38, Iteration 39, Iteration 40, Iteration 41, Iteration 42

Steps to reproduce:

1. Set up two instances of SAML, one as IdP and the other as SP.
2. Sign into IdP.
3. Navigate to Control Panel>Configuration>SAML Admin.
4. Click Replace Certificate button.
5. Create a new signing certificate to replace the current one.
6. Assert the signing certificate has been replaced.
7. Click Replace Certificate button.

Expected Result: Admin user should be able to select the previous signing certificate.
Acutal Result: No option to select the previous signing certificate.

Note: The same issue occurs when importing encrypting PCKS12 certificate.