Reset configure_boot_start var Fixes #150

[jewnix]

When running a play that installs splunk and then runs some additional tasks (like splunk_idxc_deploy.yml), it will fail at the second task because the configure_boot_start is still defined.

This resets the configure_boot_start to False at the start of the play, and fails only when the task sets it back to True

[arcsector]

Good catch on this one!