Merge pull request #643 from restebanez/master

Fixing rds mocking bug: It always shows the first instance when using servers.get

lib/fog/aws/requests/rds/describe_db_instances.rb

@@ -41,8 +41,9 @@ module Fog
             else
               raise Fog::AWS::RDS::NotFound.new("DBInstance #{identifier} not found")
             end
-          end
+          else
             server_set = self.data[:servers].values
+          end
           
           server_set.each do |server|
              case server["DBInstanceStatus"]