kotatogram-desktop: fix build with clang

(cherry picked from commit 9d6b7d5)

Author: ilya-fedin

pkgs/applications/networking/instant-messengers/telegram/kotatogram-desktop/default.nix

@@ -41,6 +41,8 @@ let
     ];
 
     nativeBuildInputs = oldAttrs.nativeBuildInputs ++ [ yasm ];
+
+    env.NIX_CFLAGS_COMPILE = lib.optionalString stdenv.cc.isClang "-Wno-c++11-narrowing";
   });
 in
 telegram-desktop.override {
@@ -80,6 +82,8 @@ telegram-desktop.override {
         libpulseaudio
       ];
 
+    env.NIX_CFLAGS_COMPILE = lib.optionalString stdenv.cc.isClang "-Wno-missing-template-arg-list-after-template-kw";
+
     meta = {
       description = "Kotatogram – experimental Telegram Desktop fork";
       longDescription = ''