Tempest: Extend http_timeout

We have occasionally seen tempest failures caused by http timeout in
CI. This extends the timeout to lower down the failure late.

Depends-on: https://review.opendev.org/880120
Change-Id: Ic13252e9adb58de3485375bb17a65c355d322afe

manifests/tempest.pp

@@ -273,6 +273,7 @@ class openstack_integration::tempest (
     debug                              => true,
     use_stderr                         => false,
     log_file                           => 'tempest.log',
+    http_timeout                       => 120,
     tempest_clone_owner                => $facts['identity']['user'],
     git_clone                          => false,
     tempest_clone_path                 => '/tmp/openstack/tempest',