Added -lpthreads in CXXFLAGS
Added -lpthreads in CXXFLAGS

raffmont/GVirtuS,raffmont/GVirtuS,RapidProjectH2020/GVirtuS,raffmont/GVirtuS,raffmont/GVirtuS,RapidProjectH2020/GVirtuS,RapidProjectH2020/GVirtuS,RapidProjectH2020/GVirtuS