When WeChat is prohibited from obtaining device information such as ID or IMEI permissions on the Android system, it will simulates the situation that WeChat cannot obtain or does not use IMEI. At this time, WeChat will use md5 (1234567890ABCDEF+uin, 32) [:7] as the key. When clearing the cache and logging in again, we can obtain a database with md5 (123456790ABCDEF+uin) [:7] as the key. this could be useful(after ver8.0.43)