Fix non working update dynamic settings

Described in elastic/elasticsearch#10614, it's not possible with cloud discovery plugin to update dynamic settings anymore.

```sh
curl -XPUT localhost:9200/_cluster/settings -d '{
    "persistent" : {
        "discovery.zen.minimum_master_nodes" : 3
    },
    "transient" : {
        "discovery.zen.minimum_master_nodes" : 3
    }
}'
```

gives

```json
{"acknowledged":true,"persistent":{},"transient":{}}
```

Closes #80.
(cherry picked from commit 7749055)
(cherry picked from commit 82bea69)

Conflicts:
	src/main/java/org/elasticsearch/discovery/azure/AzureDiscovery.java

Author: dadoonet

src/main/java/org/elasticsearch/discovery/azure/AzureDiscovery.java

@@ -21,6 +21,7 @@
 
 import org.elasticsearch.cluster.ClusterName;
 import org.elasticsearch.cluster.ClusterService;
+import org.elasticsearch.cluster.settings.ClusterDynamicSettings;
 import org.elasticsearch.cluster.settings.DynamicSettings;
 import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
@@ -42,7 +43,7 @@ public class AzureDiscovery extends ZenDiscovery {
     @Inject
     public AzureDiscovery(Settings settings, ClusterName clusterName, ThreadPool threadPool, TransportService transportService,
                           ClusterService clusterService, NodeSettingsService nodeSettingsService, ZenPingService pingService,
-                          DiscoverySettings discoverySettings, ElectMasterService electMasterService, DynamicSettings dynamicSettings) {
+                          DiscoverySettings discoverySettings, ElectMasterService electMasterService, @ClusterDynamicSettings DynamicSettings dynamicSettings) {
         super(settings, clusterName, threadPool, transportService, clusterService, nodeSettingsService,
                 pingService, electMasterService, discoverySettings, dynamicSettings);
     }