Remove extraneous lines from roles/server.json

There appear to be extra lines for the server.json role. Within them, a "monitoring" cookbook
is referenced. It appears that this cookbook does not appear in the project anywhere. Since
the reference appears on a commented line, nothing happened the first time I ran `knife solo cook`.

Being a tad OCD, I noticed this and moved the "monitoring" reference to its own line. When
I reran `knife solo cook` it failed with a "Cookbook not found" error.