Git commits in Moodle 3.8.6 by Marina Glancy

commit df6b15c7dc2cc953268ea7c676bf0ff3293da09f
Author: Marina Glancy <marina@moodle.com>
Date:   Fri, 09 Oct 2020 14:47:28 +0800
Tag:    v3.8.6

MDL-69902 core_search: fix error in the custom fields indexing