Fix: Fix Windows Cross-Compilation

Author: apocelipes

CMakeLists.txt

@@ -117,8 +117,14 @@ if(BUILD_SHARED_LIBS AND WIN32 AND HTTPLIB_COMPILE)
 	set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)
 endif()
 
-if(CMAKE_SYSTEM_NAME MATCHES "Windows" AND ${CMAKE_SYSTEM_VERSION} VERSION_LESS "10.0.0")
-	message(SEND_ERROR "Windows ${CMAKE_SYSTEM_VERSION} or lower is not supported. Please use Windows 10 or later.")
+if(CMAKE_SYSTEM_NAME MATCHES "Windows")
+	if(CMAKE_SYSTEM_VERSION)
+		if(${CMAKE_SYSTEM_VERSION} VERSION_LESS "10.0.0")
+			message(SEND_ERROR "Windows ${CMAKE_SYSTEM_VERSION} or lower is not supported. Please use Windows 10 or later.")
+		endif()
+	else()
+		message(WARNING "The target is Windows but CMAKE_SYSTEM_VERSION is not set, the default system version is set to Windows 10 or later.")
+	endif()
 endif()
 if(CMAKE_SIZEOF_VOID_P LESS 8)
 	message(WARNING "Pointer size ${CMAKE_SIZEOF_VOID_P} is not supported. Please use a 64-bit compiler.")