vsftpd: fix build with gcc15

- add patch from fedora, fixing `setup_bio_callbacks` definition

Fixes build failure with gcc15:
```
ssl.c: In function 'ssl_accept':
ssl.c:493:3: error: too many arguments to function 'setup_bio_callbacks';
expected 0, have 1
  493 |   setup_bio_callbacks(p_ssl);
      |   ^~~~~~~~~~~~~~~~~~~ ~~~~~
ssl.c:37:13: note: declared here
   37 | static void setup_bio_callbacks();
      |             ^~~~~~~~~~~~~~~~~~~
ssl.c: In function 'ssl_session_init':
ssl.c:647:3: error: too many arguments to function 'setup_bio_callbacks';
expected 0, have 1
  647 |   setup_bio_callbacks(p_ssl);
      |   ^~~~~~~~~~~~~~~~~~~ ~~~~~
ssl.c:37:13: note: declared here
   37 | static void setup_bio_callbacks();
      |             ^~~~~~~~~~~~~~~~~~~
ssl.c: At top level:
ssl.c:692:13: error: conflicting types for 'setup_bio_callbacks'; have
'void(SSL *)' {aka 'void(struct ssl_st *)'}
  692 | static void setup_bio_callbacks(SSL* p_ssl)
      |             ^~~~~~~~~~~~~~~~~~~
ssl.c:37:13: note: previous declaration of 'setup_bio_callbacks' with
type 'void(void)'
   37 | static void setup_bio_callbacks();
      |             ^~~~~~~~~~~~~~~~~~~
```

pkgs/by-name/vs/vsftpd/package.nix

@@ -2,6 +2,7 @@
   lib,
   stdenv,
   fetchurl,
+  fetchpatch,
   libcap,
   libseccomp,
   openssl,
@@ -27,7 +28,16 @@ stdenv.mkDerivation rec {
     libxcrypt
   ];
 
-  patches = [ ./CVE-2015-1419.patch ];
+  patches = [
+    ./CVE-2015-1419.patch
+
+    # Fix build with gcc15
+    (fetchpatch {
+      name = "vsftpd-correct-the-definition-of-setup_bio_callbacks-in-ssl.patch";
+      url = "https://src.fedoraproject.org/rpms/vsftpd/raw/c31087744900967ff4d572706a296bf6c8c4a68e/f/0076-Correct-the-definition-of-setup_bio_callbacks-in-ssl.patch";
+      hash = "sha256-eYiY2eKQ+qS3CiRZYGuRHcnAe32zLDdb/GwF6NyHch4=";
+    })
+  ];
 
   postPatch = ''
     sed -i "/VSF_BUILD_SSL/s/^#undef/#define/" builddefs.h