cea/readme: Cosmetic change to keep lines below 88 characters

Refs. sysadm-environment#5367

cea/Readme.md

@@ -93,7 +93,8 @@ HOSTNAME: balin024
    For example:
 
 ```
-rsync -avP ./cea/configs/preseeding swh@angrenost.internal.cea.swh.network:/var/www/html/
+$ BASTION=swh@angrenost.internal.cea.swh.network
+$ rsync -avP ./cea/configs/preseeding $BASTION:/var/www/html/
 ```
 
 5. Reboot the server with a <network card> IPV4 PXE boot device (**not IPV4