Fix install_debs script
Fix install_debs script

Some issues arose when package file was a bz2 and not a gz

pythia-project/pythia-core,pythia-project/pythia-core,pythia-project/pythia,pythia-project/pythia-core,pythia-project/pythia-core,pythia-project/pythia,pythia-project/pythia-core,pythia-project/pythia,pythia-project/pythia-core,pythia-project/pythia,pythia-project/pythia,pythia-project/pythia