[Koha] Zebra facets warning

Dear all, We have recently upgraded to 3.18 and I just noticed the following warning found in staff client under About > System Information: The <use_zebra_facets> entry is missing in your configuration file. Falling back to legacy facet calculation. How do we resolve this issue? Thank you in advance for your help. Iming ----- Iming Chan Translib Information Service Melbourne, Australia http://opac.translib.com Phone: +61 3 9801 5097 Fax: +61 3 9801 4024 E-mail: iming@translib.com -- View this message in context: http://koha.1045719.n5.nabble.com/Zebra-facets-warning-tp5821815.html Sent from the Koha-general mailing list archive at Nabble.com.