Issue 6061 - Certificate lifetime displayed as NaN

Bug Description:
HOST_TIME_GMT is filled whith an unparsable format.

Fix Description:
Using `date -Iminutes` the format is compliant with "date time string format".
Ensuring Date.parse() will always recognize it with right TZ.

Author: Adadov

Fixes: #6061

Reviewed by: @vashirov, @progier389

src/cockpit/389-console/src/lib/ldap_editor/lib/utils.jsx

@@ -998,7 +998,7 @@ export function showCertificate (certificate, showCertCallback) {
         'echo ' + certificate +
     ' | base64 --decode | openssl x509 -inform DER -noout -subject -issuer -dates -serial ;' +
     // ' echo HOST_TIME_GMT=`TZ=GMT date "+%Y-%m-%d %H:%M:%S %Z"` ' // Issue with Firefox and Safari.
-    ' echo HOST_TIME_GMT=`TZ=GMT date`'
+    ' echo HOST_TIME_GMT=`date -Iminutes`'
     ];
 
     let result = {};