Merge pull request #2935 from jackxu2011/2021.x-fix-sidecar-ip-not-set

fix: the sidecar's ip not register to nacos discovery

spring-cloud-alibaba-starters/spring-cloud-starter-alibaba-sidecar/src/main/java/com/alibaba/cloud/sidecar/nacos/SidecarNacosDiscoveryProperties.java

@@ -37,7 +37,7 @@ public class SidecarNacosDiscoveryProperties extends NacosDiscoveryProperties {
 		super.init();
 
 		String ip = sidecarProperties.getIp();
-		if (!StringUtils.hasText(ip)) {
+		if (StringUtils.hasText(ip)) {
 			this.setIp(ip);
 		}