change default to null

Author: renetapopova

modules/ROOT/pages/tools/neo4j-admin/neo4j-admin-import.adoc

@@ -228,7 +228,7 @@ It can also be specified as a percentage of the available memory, for example `7
 
 |--multiline-fields=true\|false\|<path>[,<path>]
 |label:changed[Changed in 5.26] In v1, whether or not fields from an input source can span multiple lines, i.e. contain newline characters. Setting `--multiline-fields=true` can severely degrade the performance of the importer. Therefore, use it with care, especially with large imports. In v2, this option will specify the list of files that contain multiline fields. Files can also be specified using regular expressions.
-|false
+|null
 
 |--multiline-fields-format=v1\|v2
 |label:new[Introduced in 5.26] Controls the parsing of input source that can span multiple lines, i.e. contain newline characters. When set to v1, the value for `--multiline-fields` can only be true or false. When set to v2, the value for `--multiline-fields` should be the list of files that contain multiline fields.