Fix ssl hot reload settings (opensearch-project#5116)

Signed-off-by: Andrey Pleskach <ples@aiven.io>

Author: willyborankin

src/main/java/org/opensearch/security/OpenSearchSecurityPlugin.java

@@ -2046,6 +2046,14 @@ public List<Setting<?>> getSettings() {
             settings.add(
                 Setting.boolSetting(ConfigConstants.SECURITY_SSL_CERT_RELOAD_ENABLED, false, Property.NodeScope, Property.Filtered)
             );
+            settings.add(
+                Setting.boolSetting(
+                    ConfigConstants.SECURITY_SSL_CERTIFICATES_HOT_RELOAD_ENABLED,
+                    false,
+                    Property.NodeScope,
+                    Property.Filtered
+                )
+            );
             settings.add(
                 Setting.boolSetting(
                     ConfigConstants.SECURITY_UNSUPPORTED_ACCEPT_INVALID_CONFIG,