pjsip: 2.7.2 -> 2.8 (#47735)

Semi-automatic update generated by
https://github.com/ryantm/nixpkgs-update tools. This update was made
based on information from
https://repology.org/metapackage/pjsip/versions

pkgs/applications/networking/pjsip/default.nix

···
 
 stdenv.mkDerivation rec {
   name = "pjsip-${version}";
-  version = "2.7.2";
+  version = "2.8";
 
   src = fetchurl {
     url = "http://www.pjsip.org/release/${version}/pjproject-${version}.tar.bz2";
-    sha256 = "0wiph6g51wanzwjjrpwsz63amgvly8g08jz033gnwqmppa584b4w";
+    sha256 = "0ybg0113rp3fk49rm2v0pcgqb28h3dv1pdy9594w2ggiz7bhngah";
   };
 
   buildInputs = [ openssl libsamplerate alsaLib ];