[service] extract session retrieval from "task" closure
The session was retrieved there because `set_cnxset` must be called in the same
thread as the code using it. We now retrieve the session beforehand and
explicitly call `set_cnxset`.
\.svn
^build$
^dist$
\.pyc$
\.pyo$
\.bak$
\.old$
\~$
\#.*?\#$
\.swp$
^doc/book/en/apidoc$
\.old$
syntax: regexp
.*/data/database/.*\.sqlite
.*/data/database/.*\.config
.*/data/database/tmpdb.*
.*/data/ldapdb/.*
^doc/html/
^doc/doctrees/
^doc/book/en/devweb/js_api/