fix: fix wrong env var name

README.en.md

@@ -240,7 +240,7 @@ If the channel ID is not provided, load balancing will be used to distribute the
     + Example: `CHANNEL_UPDATE_FREQUENCY=1440`
 8. `CHANNEL_TEST_FREQUENCY`: When set, it periodically tests the channels, with the unit in minutes. If not set, no test will happen.
     + Example: `CHANNEL_TEST_FREQUENCY=1440`
-9. `REQUEST_INTERVAL`: The time interval (in seconds) between requests when updating channel balances and testing channel availability. Default is no interval.
+9. `POLLING_INTERVAL`: The time interval (in seconds) between requests when updating channel balances and testing channel availability. Default is no interval.
     + Example: `POLLING_INTERVAL=5`
 
 ### Command Line Parameters

README.md

@@ -261,7 +261,7 @@ graph LR
    + 例子：`CHANNEL_UPDATE_FREQUENCY=1440`
 8. `CHANNEL_TEST_FREQUENCY`：设置之后将定期检查渠道，单位为分钟，未设置则不进行检查。
    + 例子：`CHANNEL_TEST_FREQUENCY=1440`
-9. `REQUEST_INTERVAL`：批量更新渠道余额以及测试可用性时的请求间隔，单位为秒，默认无间隔。
+9. `POLLING_INTERVAL`：批量更新渠道余额以及测试可用性时的请求间隔，单位为秒，默认无间隔。
    + 例子：`POLLING_INTERVAL=5`
 
 ### 命令行参数

common/constants.go

@@ -72,7 +72,7 @@ var RootUserEmail = ""
 
 var IsMasterNode = os.Getenv("NODE_TYPE") != "slave"
 
-var requestInterval, _ = strconv.Atoi(os.Getenv("REQUEST_INTERVAL"))
+var requestInterval, _ = strconv.Atoi(os.Getenv("POLLING_INTERVAL"))
 var RequestInterval = time.Duration(requestInterval) * time.Second
 
 const (