bugfix:SrsMetaCache memleak (#2887)
bugfix:SrsMetaCache memleak (#2887)

Co-authored-by: wanglei <b30660a0abb5f866b1d1eb3af11930d0c130674f@unicloud.com>
winlinvip/simple-rtmp-server,winlinvip/srs,winlinvip/srs,ossrs/srs,ossrs/srs,ossrs/srs,ossrs/srs,winlinvip/srs,winlinvip/srs,winlinvip/srs,ossrs/srs,winlinvip/srs,ossrs/srs