[server/sources] make sure entity._cw is a Connection before calling Storages
The storage callbacks don't get an explicit Connection objects, so they
go through entity._cw to access the repo and schedule operations. Since
that entity object comes out of the entity cache, its _cw may be a web
request instead of a Connection. So fix it up around the storage
callbacks.
Closes #5753543
[MESSAGES CONTROL]
disable-msg = C0301
[VARIABLES]
# Enable / disable this checker
enable-variables = yes
additional-builtins = _, display_name
[BASIC]
required-attributes=
attr-rgx = (w|[a-z_][a-z0-9_]{2,30})
variable-rgx = (w|[a-z_][a-z0-9_]{2,30})$
argument-rgx = (w|[a-z_][a-z0-9_]{2,30})$
[TYPECHECK]
generated-members=debug,info,notice,warning,error,critical,exception