Nix: fix install error

Fixes #214

nix/cmake.patch

@@ -0,0 +1,15 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 07e2338..720810b 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -83,9 +83,4 @@ protocol("unstable/linux-dmabuf/linux-dmabuf-unstable-v1.xml" "linux-dmabuf-unst
+ # Installation
+ install(TARGETS hyprlock)
+ 
+-install(CODE "
+-    if (NOT EXISTS \"${CMAKE_INSTALL_FULL_SYSCONFDIR}/pam.d/hyprlock\")
+-        install(FILES \"${CMAKE_SOURCE_DIR}/pam/hyprlock\" DESTINATION \"${CMAKE_INSTALL_FULL_SYSCONFDIR}/pam.d\")
+-    endif()
+-")
+-
++install(FILES "${CMAKE_SOURCE_DIR}/pam/hyprlock" DESTINATION "${CMAKE_INSTALL_FULL_SYSCONFDIR}/pam.d")

nix/default.nix

@@ -18,8 +18,14 @@
 stdenv.mkDerivation {
   pname = "hyprlock";
   inherit version;
+
   src = ../.;
 
+  patches = [
+    # remove PAM file install check
+    ./cmake.patch
+  ];
+
   nativeBuildInputs = [
     cmake
     pkg-config