Set the module's server_addr path with the mgr's name.
Set the module's server_addr path with the mgr's name.

To enable multiple mgrs to run properly, we need to set the respective server_addr path with the mgr's name for the modules of each mgr.

When multiple mgrs are running, the modules( e.g. dashboard and Prometheus ) of each mgr need to bind its own server_addr when it is started. The way to get server_addr when ceph mgr starts the module is as follows:  first,  get the server_addr value by "mgr/<module-name>/<mgr-daemonid>/server_addr" path;  and if this path does not exist, then get the server_addr value by" mgr/<module-name>/server_addr" path.
According to the original rook setting for server_addr,  the modules of all mgrs take the same server_addr on ceph luminous and mimic, this produces a wrong result that only one mgr's modules can run properly ( the modules of other mgrs failed to start with the wrong server_addr).
This change is made to be compatible with ceph luminous, mimic, and nautilus.  and Modify according to: the "HOST NAME AND PORT" description of http://docs.ceph.com/docs/master/mgr/dashboard/ .

Signed-off-by: wangxiao86 <901c100b800d30db3bf429e5b7b35fecd7145689@sensetime.com>

rook/nfs,rook/rook,rook/rook,rook/rook,rook/rook,rook/nfs,rook/rook,rook/nfs