Fix build with Boost 1.91

Index: CMakeLists.txt
--- CMakeLists.txt.orig
+++ CMakeLists.txt
@@ -155,7 +155,6 @@ find_package(Boost REQUIRED COMPONENTS
 	iostreams
 	filesystem
 	date_time
-	system
 	program_options
 )
 list(APPEND LIBRARIES ${Boost_LIBRARIES})
