Resolve insecure runpath issue.

--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -17,6 +17,7 @@
   set(CMAKE_INSTALL_INCLUDEDIR "include")
 endif()
 
+set(CMAKE_BUILD_WITH_INSTALL_RPATH TRUE)
 if (POLICY CMP0074)
   # use environment variables to find libraries
   cmake_policy(SET CMP0074 NEW)