Fixed bug in `calculate_ip_detect_public_contents()`.
Fixed bug in `calculate_ip_detect_public_contents()`.

Previously, the calculate_ip_detect_public_contents() function would
throw away the value of calculate_ip_detect_contents() in the case where
ip_detect_public_filename is passed in. Now it doesn't.

surdy/dcos,mellenburg/dcos,mellenburg/dcos,mesosphere-mergebot/dcos,vishnu2kmohan/dcos,kensipe/dcos,asridharan/dcos,GoelDeepak/dcos,mellenburg/dcos,asridharan/dcos,BenWhitehead/dcos,surdy/dcos,mesosphere-mergebot/dcos,dcos/dcos,vishnu2kmohan/dcos,surdy/dcos,dcos/dcos,BenWhitehead/dcos,lingmann/dcos,lingmann/dcos,amitaekbote/dcos,jeid64/dcos,dcos/dcos,kensipe/dcos,mellenburg/dcos,kensipe/dcos,jeid64/dcos,mesosphere-mergebot/dcos,amitaekbote/dcos,GoelDeepak/dcos,branden/dcos,asridharan/dcos,jeid64/dcos,amitaekbote/dcos,mesosphere-mergebot/mergebot-test-dcos,BenWhitehead/dcos,dcos/dcos,lingmann/dcos,asridharan/dcos,branden/dcos,mesosphere-mergebot/mergebot-test-dcos,branden/dcos,lingmann/dcos,vishnu2kmohan/dcos,surdy/dcos,mesosphere-mergebot/mergebot-test-dcos,vishnu2kmohan/dcos,amitaekbote/dcos,jeid64/dcos,GoelDeepak/dcos,mesosphere-mergebot/dcos,dcos/dcos,branden/dcos,BenWhitehead/dcos,mesosphere-mergebot/mergebot-test-dcos,GoelDeepak/dcos,kensipe/dcos