HHH-8364 exclude-unlisted-classes parsing handles content incorrectly

Parsing for exclude-unlisted-classes handles content within the element incorrectly. The value correctly defaults to false. <exclude-unlisted-classes /> and <exclude-unlisted-classes>true</exclude-unlisted-classes> are correctly parsed as true. However, <exclude-unlisted-classes>false</exclude-unlisted-classes> is incorrectly parsed as true. This commit fixes that.