COOK-3536 Extra check to make sure cloud local_ipv4 actually exist

Mysql fails to install on Linode because of cloud local_ipv4 attribute 



I spent couple days figuring out this issue. Turned out that on Linode node.attribute?('cloud') == true, node.cloud['local_ipv4'] is not set.

As the result mysql just wont start with socket error.

More details here:

http://distinctplace.com/infrastructure/2013/08/28/percona-mysql-install-problem-with-chef-on-linode---be-aware/

Here is the output of linode cloud attributes:

"cloud": { "public_ips": [ "176.56.102.37" ], "private_ips": [ null ], "public_ipv4": null, "public_hostname": null, "local_ipv4": null, "local_hostname": null, "provider": "linode" }