[client] servers: Remove unused 'add monitoring server (new version)' button for development.

The button was used during development phase and is not used any longer.
Remove it.

Signed-off-by: YOSHIFUJI Hideaki <hideaki.yoshifuji@miraclelinux.com>
Merge pull request #723 from project-hatohol/remove-unused-button-20141021

[client] servers: Remove unused 'add monitoring server (new version)' bu...