don't install external component

Index: rts/lib/lunasvg/CMakeLists.txt
--- rts/lib/lunasvg/CMakeLists.txt.orig
+++ rts/lib/lunasvg/CMakeLists.txt
@@ -27,14 +27,3 @@ endif()
 
 set(LUNASVG_LIBDIR ${CMAKE_INSTALL_PREFIX}/lib)
 set(LUNASVG_INCDIR ${CMAKE_INSTALL_PREFIX}/include)
-
-install(FILES
-    include/lunasvg.h
-    DESTINATION ${LUNASVG_INCDIR}
-)
-
-install(TARGETS lunasvg
-    LIBRARY     DESTINATION    ${LUNASVG_LIBDIR}
-    ARCHIVE     DESTINATION    ${LUNASVG_LIBDIR}
-    INCLUDES    DESTINATION    ${LUNASVG_INCDIR}
-)
