[Release-1.27] - rke2-server creates improper etcd member name

[brandond]

Backport fix for rke2-server creates improper etcd member name

• rke2-server creates improper etcd member name #5482

[VestigeJ]

Reproduced and steps over here - #5482 (comment)

Validation:

$ get_etcd

+------------------+---------+------------------------------------------------+---------------------------+---------------------------+------------+
|        ID        | STATUS  |                      NAME                      |        PEER ADDRS         |       CLIENT ADDRS        | IS LEARNER |
+------------------+---------+------------------------------------------------+---------------------------+---------------------------+------------+
|  52d5fdef4222838 | started | justjustv127rke2-pool1-ba1ba2d0-x92l9-2fb96d2e | https://1.1.1.164:2380    | https://1.1.1.164:2379    |      false |
| c1945e561669f92a | started | justjustv127rke2-pool1-ba1ba2d0-xchkh-603350a4 |  https://1.1.1.11:2380     |  https://1.1.1.11:2379    |      false |
| f16d64728fa8bd42 | started | justjustv127rke2-pool1-ba1ba2d0-7l5js-8c598301 | https://1.1.1.171:2380    | https://1.1.1.171:2379    |      false |
+------------------+---------+------------------------------------------------+---------------------------+---------------------------+------------+

$ rke2 -v

rke2 version v1.27.12-rc1+rke2r1 (25b27b4e4709a2ac4c550609ad730a9e172d110a)
go version go1.21.8 X:boringcrypto