[web] fix os.rename usage on windows when destination exists
os.rename on windows will raise OSError (or WindowsError subclass) when if
destination file already exists.
Also check that exception is EEXIST.
There is an attempt to fix in f6ba947c but using IOError instead of OSError.
Closes #14214794
addressbook
basket
blog
book
calendar
comment
company
email
file
folder
i18ncontent
keyword
link
mailinglist
person
tag
timeseries
vcsfile