shell: fix lively.shell.exec
shell: fix lively.shell.exec

LivelyKernel/LivelyKernel,pascience/LivelyKernel,LivelyKernel/LivelyKernel,NikolaySuslov/LivelyKernel,NikolaySuslov/LivelyKernel,LivelyKernel/LivelyKernel,NikolaySuslov/LivelyKernel,pascience/LivelyKernel,pascience/LivelyKernel