spring boot应用启动时，报不要使用@符号的错误：
…
Caused by: org.yaml.snakeyaml.scanner.ScannerException: while scanning for the next token
found character ‘@’ that cannot start any token. (Do not use @ for indentation)
in ‘reader’, line 2, column 11:
@oldLocalSendDir@
…
可以使用双引号将其引用起来，改为 “@oldLocalSendDir@”。