Increase sleep timeout for 'waiting-for-neutron-api' for CI stabilization

Deployment on the CI stand fails with an error - the neutron server does
not manage successfully start, need increase check timeout.

Change-Id: Ifefe0c3b7425ddfcfd30c5d8d947575749c913ab

deployment_scripts/puppet/manifests/neutron-server-start.pp

@@ -62,7 +62,7 @@ if 'primary-controller' in hiera('roles') {
     ],
     path        => '/usr/sbin:/usr/bin:/sbin:/bin',
     tries       => '30',
-    try_sleep   => '4',
+    try_sleep   => '15',
     command     => 'neutron net-list --http-timeout=4 2>&1 > /dev/null',
     provider    => 'shell',
     subscribe   => Service['neutron-server'],