[api2] Fix extracting email from user notification detail
[api2] Fix extracting email from user notification detail

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