False positive for `dbDelta` when using "ignoreWordPressSymbols"

[thomas-price]

With configuration:

	<rule ref="ImportDetection"/>
	<rule ref="ImportDetection.Imports.RequireImports">
		<properties>
			<property name="ignoreWordPressSymbols" value="true"/>
		</properties>
	</rule>

A false positive is occurring: "Found unimported symbol 'dbDelta'." I can see dbdelta (lowercase) is included in WordPressSymbols.php. Question: Should the symbol list be case insensitive, if not, should dbDelta also be included?

thank you