[thumbnail] use posixpath to generate thumbnail-src
[thumbnail] use posixpath to generate thumbnail-src

Chilledheart/seahub,madflow/seahub,cloudcopy/seahub,Chilledheart/seahub,madflow/seahub,cloudcopy/seahub,miurahr/seahub,Chilledheart/seahub,madflow/seahub,Chilledheart/seahub,madflow/seahub,miurahr/seahub,Chilledheart/seahub,cloudcopy/seahub,miurahr/seahub,cloudcopy/seahub,madflow/seahub,miurahr/seahub