Better Fedora download site

- The link from the official Fedora site takes to a FTP
  site that won't work in Spain. So we are using a high
  bandwidth mirror by now.

lib/Ravada.pm

@@ -171,7 +171,7 @@ sub _update_isos {
         ,fedora => {
             name => 'Fedora 25'
             ,description => 'RedHat Fedora 25 Workstation 64 bits'
-            ,url => 'https://download.fedoraproject.org/pub/fedora/linux/releases/25/Workstation/x86_64/iso/Fedora-Workstation-netinst-x86_64-25-.*\.iso'
+            ,url => 'http://ftp.halifax.rwth-aachen.de/fedora/linux/releases/25/Workstation/x86_64/iso/Fedora-Workstation-netinst-x86_64-25-.*\.iso'
             ,arch => 'amd64'
             ,xml => 'xenial64-amd64.xml'
             ,xml_volume => 'xenial64-volume.xml'