fixed bug

im-sdk/src/main/java/com/wecloud/im/sdk/internal/WecloudImUserOperation.java

@@ -116,10 +116,9 @@ public class WecloudImUserOperation extends WecloudImOperation {
         String nickname = modifyUserRequest.getNickname();
         // 参数校验
         assertParameterNotNull(userId, "userId");
-        assertParameterNotBlank(nickname, "nickname");
         // 校验通过 构建参数
         Map<String, Object> param = new HashMap<>();
-        param.put("userId", userId + "");
+        param.put("client", userId + "");
         param.put("headPortrait", headPortrait);
         param.put("nickname", nickname);
         // 发送请求