Revert "fix shell invocation"
Revert "fix shell invocation"

This reverts commit 1d67f166b54e0d8df1f0f4e76ec25d677ab6b18c.

luis-rr/saga-python,telamonian/saga-python,mehdisadeghi/saga-python,telamonian/saga-python,mehdisadeghi/saga-python,luis-rr/saga-python,luis-rr/saga-python