* Revert "There can be only one localhost"
This reverts commit 5f1bbb4fcd.
this broke several usages of localhost, see #16882, #16898 and #16886
* ensure there is only 1 localhost
fixes#16886, #16882 and #16898
- make sure localhost exists before returning it
- optimzed host caching
- ensure we always return a host object
(cherry picked from commit f7570f1dc4)
df16e37ad7