pdo: free connection before commit(), rollback()
pdo: free connection before commit(), rollback()

ref https://github.com/peachpiecompiler/peachpie/issues/990

peachpiecompiler/peachpie,iolevel/peachpie-concept,iolevel/peachpie-concept,iolevel/peachpie-concept,peachpiecompiler/peachpie,peachpiecompiler/peachpie