fix: redis install fails

I fixed the following error.
Tested to work with CentOS 6.5 and Ubuntu 14.04.

Error log
```
Starting Chef Client, version 11.14.6
Compiling Cookbooks...

================================================================================
Recipe Compile Error in /home/yutaka/chef-solo/cookbooks-2/sensu/recipes/redis.rb
================================================================================

Chef::Exceptions::ResourceNotFound
----------------------------------
Cannot find a resource matching service[redis6379] (did you define it first?)

Cookbook Trace:
---------------
  /home/yutaka/chef-solo/cookbooks-2/redisio/recipes/enable.rb:25:in `block in from_file'
  /home/yutaka/chef-solo/cookbooks-2/redisio/recipes/enable.rb:23:in `each'
  /home/yutaka/chef-solo/cookbooks-2/redisio/recipes/enable.rb:23:in `from_file'
  /home/yutaka/chef-solo/cookbooks-2/sensu/recipes/redis.rb:23:in `from_file'

Relevant File Content:
----------------------
/home/yutaka/chef-solo/cookbooks-2/redisio/recipes/enable.rb:

 18:  # limitations under the License.
 19:  #
 20:  
 21:  redis = node['redisio']
 22:  
 23:  redis['servers'].each do |current_server|
 24:    server_name = current_server["name"] || current_server["port"]
 25>>   resource = resources("service[redis#{server_name}]")
 26:    resource.action Array(resource.action)
 27:    resource.action << :start
 28:    resource.action << :enable
 29:  end
 30:  

Running handlers:
[2014-09-08T08:57:14+09:00] ERROR: Running exception handlers
Running handlers complete
[2014-09-08T08:57:14+09:00] ERROR: Exception handlers complete
[2014-09-08T08:57:14+09:00] FATAL: Stacktrace dumped to /var/chef/cache/chef-stacktrace.out
Chef Client failed. 0 resources updated in 2.160438311 seconds
[2014-09-08T08:57:14+09:00] ERROR: Cannot find a resource matching service[redis6379] (did you define it first?)
[2014-09-08T08:57:14+09:00] FATAL: Chef::Exceptions::ChildConvergeError: Chef run process exited unsuccessfully (exit code 1)
ERROR: RuntimeError: chef-solo failed. See output above.
```