🐛 fix: User attribute is empty, it will cause the conditional match to fail

Author: jianggang

pom.xml

@@ -5,7 +5,7 @@
 
     <groupId>com.featureprobe</groupId>
     <artifactId>server-sdk-java</artifactId>
-    <version>2.2.0</version>
+    <version>2.2.1</version>
     <name>server-sdk-java</name>
     <description>FeatureProbe Server Side SDK for Java</description>