message: Enrich distro detection code
diff: # /usr/bin/x86_64-linux-gnu-ld: /usr/lib/gcc/x86_64-linux-gnu/8/../../../x86_64-linux-gnu/libltdl.a(libltdl_libltdl_la-lt__alloc.o): relocation R_X86_64_PC32 against symbol `stderr@@GLIBC_2.2.5' can not be used when making a shared object; recompile with -fPIC
  if (NOT BUILD_SHARED)
  - execute_process(COMMAND lsb_release -is OUTPUT_VARIABLE _distname OUTPUT_STRIP_TRAILING_WHITESPACE)
  - message (STATUS "lsb_release -cs: ${_distname}")
  + execute_process(
  + COMMAND lsb_release -is
  + OUTPUT_VARIABLE _distname
  + OUTPUT_STRIP_TRAILING_WHITESPACE
  + )
  + if (_distname)
  + message (STATUS "lsb_release -is: ${_distname}")
  + else ()
  + execute_process(
  + COMMAND sh -c "head -n 1 /etc/issue | cut -f 1 -d ' '"
  + OUTPUT_VARIABLE _distname
  + OUTPUT_STRIP_TRAILING_WHITESPACE
  + )
  + if (_distname)
  + message (STATUS "Distro name from /etc/issue: ${_distname}")
  + endif
  + endif
  +
  if (_distname STREQUAL "Ubuntu" OR _distname STREQUAL "Debian")
  list (REVERSE CMAKE_FIND_LIBRARY_SUFFIXES)
  set (_suffixes_reversed 1)
  