message: fix FreeBSD build
diff: @@ -62,6 +62,11 @@ if(UNIX) # APPLE, LINUX, FREE_BSD
  set(CMAKE_CXX_FLAGS_RELEASE "${PCM_OPTIONAL_FLAGS} -O3 -D_FORTIFY_SOURCE=1 -rdynamic")
  set(CMAKE_CXX_FLAGS_DEBUG "${PCM_OPTIONAL_FLAGS} -O0 -g -rdynamic")
  set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "${PCM_OPTIONAL_FLAGS} -O3 -g -D_FORTIFY_SOURCE=1 -rdynamic")
  + if(FREE_BSD)
  + set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -lexecinfo")
  + set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -lexecinfo")
  + set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO} -lexecinfo")
  + endif(FREE_BSD)
  set(CMAKE_C_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE}")
  set(CMAKE_C_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG}")
  set(CMAKE_C_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO}")
  