Fix headers when output is piped for oneacct and oneshowback

[OpenNebulaProject]

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Author Name: Carlos Martín (Carlos Martín)
Original Redmine Issue: 3337, https://dev.opennebula.org/issues/3337
Original Date: 2014-11-13

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Most cli commands do not use bold chars when the output is a pipe, see CLIHelper.print_header
oneacct and oneshowback should do the same

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This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions. The OpenNebula Dev Team

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This issue has been automatically closed due to lack of activity/feedback. Please reopen if you have further input or need to bump this. The OpenNebula Dev Team