Fix bug for array-formatted identities of user mappings

I failed to realize that server names reported in the object args array
would get quoted, which is wrong; remove that, making sure that it's
only quoted in the string-formatted identity.

This bug was introduced by my commit cf34e373, which was backpatched,
but since object name/args arrays are new in commit a6762014, there
is no need to backpatch this any further.