Merge pull request ipaddress-gem#28 from Adam21e/remove_dup_from_summarize

Remove dup from ipv6 summarize to give small performance boost

Author: Adam21e

lib/ipaddress_2/ipv6.rb

@@ -989,17 +989,18 @@ def self.parse_hex(hex, prefix=128)
     def self.summarize(*args)
       # one network? no need to summarize
       return [args.first.network] if args.size == 1
+      args_size = args.size 
 
       i = 0
-      result = args.dup.sort.map{|ip| ip.network}
+      result = args.sort.map{|ip| ip.network}
       while i < result.size-1
         sum = result[i] + result[i+1]
         result[i..i+1] = sum.first if sum.size == 1
         i += 1
       end
 
       result.flatten!
-      if result.size == args.size
+      if result.size == args_size
         # nothing more to summarize
         return result
       else