Fix wrong cluster configuration used when multiple match

When using lanpower on abacus25-2, lanpower took the first matching cluster configuration. So if we have both abacus2 and abacus25 in the configuration, lanpower just took the first declared.

This commit change that: now when using lanpower on abacus25-2, lanpower now look for an exact match of abacus25 in the configuration.

lib/lanpower/application/lanpower.rb

@@ -224,13 +224,14 @@ class Lanpower::Application::Lanpower < Lanpower::Application
 
   def getnode(arg)
     shortname = arg.split('.')[0]
+    clustername = shortname.split('-')[0]
     # Node-specific configuration
     nodename = @nodes_keys.select { |n| shortname == n }.first
     if !nodename.nil?
       node = @conf.value["nodes"][nodename]
     else
       # Cluster-wide configuration
-      cluster = @clusters.select { |c| !arg.match(c).nil? }.first
+      cluster = @clusters.select { |c| clustername == c }.first
       if !cluster.nil?
         node = @conf.value["clusters"][cluster]
       else