web_backend: fix a regression introduced in 39c8d18

* A regression was in 39c8d18 and token verification function was
  broken.
* The reason being `httplib` now requires OpenSSL 1.1+ API while
  LibreSSL 2.x provided OpenSSL 1.0 compatible API.
* The bundled LibreSSL has been updated to 3.2.2 so it now provides
  OpenSSL 1.1 compatible API now.
* Also the path hint has been added so that it will find the correct
  path to the CA certs on *nix systems.
* An option is provided so that *nix system distributions/providers can
  use their own SSL implementations when compiling Yuzu/Citra to
  (hopefully) complies with their maintenance guidelines.
* LURLParse is also removed since `httplib` can handle
  `scheme:host:port` string itself now.

externals/CMakeLists.txt

@@ -73,17 +73,20 @@ if (NOT LIBZIP_FOUND)
 endif()
 
 if (ENABLE_WEB_SERVICE)
-    # LibreSSL
-    set(LIBRESSL_SKIP_INSTALL ON CACHE BOOL "")
-    add_subdirectory(libressl EXCLUDE_FROM_ALL)
-    target_include_directories(ssl INTERFACE ./libressl/include)
-    target_compile_definitions(ssl PRIVATE -DHAVE_INET_NTOP)
-    get_directory_property(OPENSSL_LIBRARIES
-        DIRECTORY libressl
-        DEFINITION OPENSSL_LIBS)
-
-    # lurlparser
-    add_subdirectory(lurlparser EXCLUDE_FROM_ALL)
+    if (USE_SYSTEM_SSL)
+        find_package(OpenSSL 1.1 REQUIRED)
+        set(OPENSSL_LIBRARIES OpenSSL::SSL OpenSSL::Crypto)
+    else()
+        # LibreSSL
+        set(LIBRESSL_SKIP_INSTALL ON CACHE BOOL "")
+        set(OPENSSLDIR "/etc/ssl/")
+        add_subdirectory(libressl EXCLUDE_FROM_ALL)
+        target_include_directories(ssl INTERFACE ./libressl/include)
+        target_compile_definitions(ssl PRIVATE -DHAVE_INET_NTOP)
+        get_directory_property(OPENSSL_LIBRARIES
+            DIRECTORY libressl
+            DEFINITION OPENSSL_LIBS)
+    endif()
 
     # httplib
     add_library(httplib INTERFACE)