CBQE-7478: Additional fix for GSI backup in x509

Adds the correct cert parameter for x509 tests

Change-Id: I30be0d734f0693fd3df64073a3418d42c945777e
Reviewed-on: https://review.couchbase.org/c/testrunner/+/171425
Tested-by: Joe Mitchell Jones <joe.mitchelljones@couchbase.com>
Reviewed-by: Thuan Nguyen <soccon@gmail.com>

pytests/ent_backup_restore/enterprise_backup_restore_test.py

@@ -3477,6 +3477,8 @@ def test_backup_restore_with_gsi(self):
 
         cmd = "cbindex -type list -auth %s:%s" % (self.master.rest_username,
                                                   self.master.rest_password)
+        if self.input.param("x509", False):
+            cmd += f" -use_tls -cacert {self.x509.CACERTFILEPATH}all/all_ca.pem"
         shell = RemoteMachineShellConnection(self.backupset.restore_cluster_host)
         command = "{0}/{1}".format(self.cli_command_location, cmd)
         output, error = shell.execute_command(command)