CMake: Avoid reordering CMAKE_CXX_FLAGS

Order matters; the reordering caused the _FORTIFY_SOURCE flag to be
always undefined (as we flipped a "-U" and "-D")

Also skip removing duplicates to avoid similar pitfalls (we kept
only the first occurrence but should've kept the last)
It did not work properly anyway (we still had duplicates in the end)
and was only required as we wrote the final CMAKE_CXX_FLAGS back to
cache and consequently appended new flags with every run of CMAKE.

0 files changed, 0 insertions, 0 deletions