Add empty cleandb target for consistency.
Add empty cleandb target for consistency.

tcmitchell/geni-portal,charliemeyer/geni-portal,charliemeyer/geni-portal,tcmitchell/geni-portal,charliemeyer/geni-portal,tcmitchell/geni-portal,tcmitchell/geni-portal,tcmitchell/geni-portal,charliemeyer/geni-portal,charliemeyer/geni-portal