Fix Fedora /etc/hosts bug

Update so that localhost entries don't get deleted when the hostname
gets added to the 127.0.0.1 line. Closes #6202

plugins/guests/fedora/cap/change_host_name.rb

@@ -48,7 +48,7 @@ module VagrantPlugins
         def update_etc_hosts
           ip_address = '([0-9]{1,3}\.){3}[0-9]{1,3}'
           search     = "^(#{ip_address})\\s+#{Regexp.escape(current_hostname)}(\\s.*)?$"
-          replace    = "\\1 #{fqdn} #{short_hostname}"
+          replace    = "\\1 #{fqdn} #{short_hostname} \\3"
           expression = ['s', search, replace, 'g'].join('@')
 
           sudo("sed -ri '#{expression}' /etc/hosts")
@@ -72,4 +72,4 @@ module VagrantPlugins
       end
     end
   end
-end
+end