gns3Packages.{server,gui}Preview: 2.2.0rc3 -> 2.2.0rc4

pkgs/applications/networking/gns3/default.nix

···
 
 let
   stableVersion = "2.1.21";
-  previewVersion = "2.2.0rc3";
+  previewVersion = "2.2.0rc4";
   addVersion = args:
     let version = if args.stable then stableVersion else previewVersion;
         branch = if args.stable then "stable" else "preview";
···
   };
   guiPreview = mkGui {
     stable = false;
-    sha256Hash = "0lj2av2kbh1drr8jzd71j85xaiwp53q1g348lk2qqzr35yh16n99";
+    sha256Hash = "14fzjaanaxya97wrya2lybxz6qv72fk4ws8i92zvjz4jkvjdk9n3";
   };
 
   serverStable = mkServer {
···
   };
   serverPreview = mkServer {
     stable = false;
-    sha256Hash = "0a4gx0qhy50v7nivqn8c2kz07crgzg2105hzmwag8xw6bpqmgm1d";
+    sha256Hash = "03s2kq5f8whk14rhprg9yp3918641b1cwj6djcbjw8xpz0n3w022";
   };
 }