Revert "tests/acceptance/17_packages/multiline_yum_check_update.cf: s/staged/staging/ oops"

This reverts commit df42fda9d5e82579d6b5a334f0290774204b18a4.
Revert "tests/acceptance/17_packages/multiline_yum_check_update.cf: staged for now, failing in 3.6.x"

This reverts commit 56b5a8f3949461766e59a0a2c6aa1c8c4f5c6b23.
promises.cf: don't run lsb detection on non-linux unixes

(cherry picked from commit bb6b2db8539516feb816822604778d2990676dc6)