lwm2m: add bootstrap DTLS config - SERVER_ONLY

common/transport/lwm2m/src/main/java/org/thingsboard/server/transport/lwm2m/bootstrap/LwM2MTransportBootstrapService.java

@@ -32,7 +32,6 @@ import org.thingsboard.server.transport.lwm2m.bootstrap.store.LwM2MBootstrapSecu
 import org.thingsboard.server.transport.lwm2m.bootstrap.store.LwM2MInMemoryBootstrapConfigStore;
 import org.thingsboard.server.transport.lwm2m.config.LwM2MTransportBootstrapConfig;
 import org.thingsboard.server.transport.lwm2m.config.LwM2MTransportServerConfig;
-import org.thingsboard.server.transport.lwm2m.server.DefaultLwM2mTransportService;
 
 import javax.annotation.PostConstruct;
 import javax.annotation.PreDestroy;
@@ -84,6 +83,8 @@ public class LwM2MTransportBootstrapService {
 
         /* Create and Set DTLS Config */
         DtlsConnectorConfig.Builder dtlsConfig = new DtlsConnectorConfig.Builder(getCoapConfig(bootstrapConfig.getPort(), bootstrapConfig.getSecurePort(), serverConfig));
+
+        dtlsConfig.set(DtlsConfig.DTLS_ROLE, DtlsConfig.DtlsRole.SERVER_ONLY);
         dtlsConfig.set(DTLS_RECOMMENDED_CURVES_ONLY, serverConfig.isRecommendedSupportedGroups());
         dtlsConfig.set(DTLS_RECOMMENDED_CIPHER_SUITES_ONLY, serverConfig.isRecommendedCiphers());