Fix trailing whitespace at the end of headers.cpp_flags (#4957)
Fix trailing whitespace at the end of headers.cpp_flags (#4957)


EmreAtes/spack,mfherbst/spack,matthiasdiener/spack,TheTimmy/spack,matthiasdiener/spack,skosukhin/spack,matthiasdiener/spack,iulian787/spack,krafczyk/spack,mfherbst/spack,krafczyk/spack,krafczyk/spack,mfherbst/spack,TheTimmy/spack,EmreAtes/spack,lgarren/spack,lgarren/spack,matthiasdiener/spack,LLNL/spack,tmerrick1/spack,iulian787/spack,lgarren/spack,tmerrick1/spack,EmreAtes/spack,skosukhin/spack,mfherbst/spack,iulian787/spack,LLNL/spack,LLNL/spack,LLNL/spack,tmerrick1/spack,skosukhin/spack,krafczyk/spack,iulian787/spack,skosukhin/spack,TheTimmy/spack,LLNL/spack,matthiasdiener/spack,skosukhin/spack,iulian787/spack,mfherbst/spack,lgarren/spack,lgarren/spack,TheTimmy/spack,krafczyk/spack,TheTimmy/spack,EmreAtes/spack,tmerrick1/spack,EmreAtes/spack,tmerrick1/spack