Enable variable input for HTTPS Port

Change-Id: Ic8c95da1eb0df94e0f243be5201f50169d85aa1e
Signed-off-by: Anusha Dathatri <adathatr@in.ibm.com>
diff --git a/lib/certificate_utils.robot b/lib/certificate_utils.robot
index b68fe6a..7a8bdcc 100755
--- a/lib/certificate_utils.robot
+++ b/lib/certificate_utils.robot
@@ -46,7 +46,7 @@
     Check If Openssl Tool Exist
 
     ${openssl_cmd}=  Catenate
-    ...  timeout 10  openssl s_client -connect ${OPENBMC_HOST}:443 -showcerts
+    ...  timeout 10  openssl s_client -connect ${OPENBMC_HOST}:${HTTPS_PORT} -showcerts
     ${output}=  Run  ${openssl_cmd}
 
     ${result}=  Fetch From Left