FastCGI Handler should not rebind to host/port if file is set.

File should override Port/Host so that things like Rackup that *always* pass in a host/port combination can be overriden by the File parameter. This change makes that happen.

lib/rack/handler/fastcgi.rb

@@ -19,8 +19,11 @@ module Rack
   module Handler
     class FastCGI
       def self.run(app, options={})
-        file = options[:File] and STDIN.reopen(UNIXServer.new(file))
-        port = options[:Port] and STDIN.reopen(TCPServer.new(options[:Host], port))
+        if options[:File]
+          file = STDIN.reopen(UNIXServer.new(options[:File]))
+        elsif options[:Port]
+          port = STDIN.reopen(TCPServer.new(options[:Host], options[:Port]))
+        end
         FCGI.each { |request|
           serve request, app
         }