Update Hellhound.xml

Trying to fix

data/raids/Hellhound.xml:12: parser error : Opening and ending tag mismatch: are
aspawn line 6 and raid
</raid>
       ^
data/raids/Hellhound.xml:13: parser error : Premature end of data in tag raid line 1
^
[14:19:15.900] [Error - Raid::loadFromXml] Could not load raid file (data/raids/Hellhound.xml).
[14:19:15.900] Line: 13, Info: Premature end of data in tag raid line 1
[14:19:15.900] [Fatal - Raids::parseRaidNode] failed to load raid Hellhound