📤 Use nlohmann_json tar release (#259)

* 📤 Use nlohmann_json tar release

This avoids downloading the whole git repository and restricts the download
to the pieces that are actually important, saving time and traffic.

Author: Thalhammer

CMakeLists.txt

@@ -1,4 +1,8 @@
 cmake_minimum_required(VERSION 3.14)
+cmake_policy(VERSION 3.14)
+if(POLICY CMP0135) # DOWNLOAD_EXTRACT_TIMESTAMP
+  cmake_policy(SET CMP0135 OLD)
+endif()
 
 # HUNTER_ENABLED is always set if this package is included in a project using hunter (HunterGate sets it) In this case
 # we will use hunter as well to stay consistent. If not the use can supply it on configure to force using hunter.
@@ -65,11 +69,13 @@ endif()
 find_package(nlohmann_json CONFIG)
 
 if(NOT nlohmann_json_FOUND)
+  message(STATUS "jwt-cpp: using FetchContent for nlohmann json")
   include(FetchContent)
-
-  fetchcontent_declare(nlohmann_json GIT_REPOSITORY https://github.com/nlohmann/json.git GIT_TAG v3.11.2)
-
-  fetchcontent_makeavailable(nlohmann_json)
+  FetchContent_Declare(nlohmann_json
+      URL https://github.com/nlohmann/json/releases/download/v3.11.2/json.tar.xz
+      URL_MD5 127794b2c82c0c5693805feaa2a703e2
+  )
+  FetchContent_MakeAvailable(nlohmann_json)
 endif()
 
 set(JWT_INCLUDE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/include)