Core/Spells: Fix Lifeblood scaling with health

Based on Kapoeira's patch

Closes #817 and pull request #13

sql/scripts/world_scripts_full.sql

@@ -1911,6 +1911,7 @@ INSERT INTO `spell_script_names` (`spell_id`,`ScriptName`) VALUES
 ( 57593, 'spell_generic_clone_weapon'),
 ( 52408, 'spell_gen_seaforium_blast'),
 ( 25281, 'spell_gen_turkey_marker'),
+(-55428, 'spell_gen_lifeblood'),
 -- instances
 -- Black Temple
 ( 41475, 'spell_boss_lady_malande_shield'),