addListener and getConfig used different path

[uglycow]

• I have searched the issues of this repository and believe that this is not a duplicate.
• I have checked the FAQ of this repository and believe that this is not a duplicate.

Environment

• Dubbo version: 2.7.2
• Operating System version: xxx
• Java version: xxx

Steps to reproduce this issue

public void removeListener(String key, String group, ConfigurationListener listener) {
        cacheListener.removeListener(key, listener);
    }

    @Override
    public String getConfig(String key, String group, long timeout) throws IllegalStateException {
        /**
         * when group is not null, we are getting startup configs from Config Center, for example:
         * group=dubbo, key=dubbo.properties
         */
        if (StringUtils.isNotEmpty(group)) {
            key = group + "/" + key;
        }
        /**
         * when group is null, we are fetching governance rules, for example:
         * 1. key=org.apache.dubbo.DemoService.configurators
         * 2. key = org.apache.dubbo.DemoService.condition-router
         */
        else {
            int i = key.lastIndexOf(".");
            key = key.substring(0, i) + "/" + key.substring(i + 1);
        }

        return (String) getInternalProperty(rootPath + "/" + key);
    }

addListener and getConfig used different path, so only one of the could get data from configcenter

Pls. provide [GitHub address] to reproduce this issue.

Expected Result

What do you expected from the above steps？

Actual Result

What actually happens?

If there is an exception, please attach the exception trace:

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