Don't link against SDL2main (#265)

source/Irrlicht/CMakeLists.txt

@@ -523,7 +523,7 @@ target_link_libraries(IrrlichtMt PRIVATE
 	${ZLIB_LIBRARY}
 	${JPEG_LIBRARY}
 	${PNG_LIBRARY}
-	"$<$<BOOL:${USE_SDL2}>:${SDL2_LIBRARIES}>"
+	"$<$<BOOL:${USE_SDL2}>:SDL2::SDL2>"
 
 	"$<$<BOOL:${OPENGL_DIRECT_LINK}>:${OPENGL_LIBRARIES}>"
 	"$<$<BOOL:${OPENGLES_DIRECT_LINK}>:${OPENGLES_LIBRARY}>"