DB/Spells: fix proc regression with Missile Barrage

Closes #21466

sql/updates/world/3.3.5/2018_02_21_00_world_335.sql

@@ -0,0 +1 @@
+UPDATE `spell_proc` SET `ProcFlags`=65536 WHERE `SpellId`=44401;

src/server/game/Spells/SpellMgr.cpp

@@ -2886,6 +2886,13 @@ void SpellMgr::LoadSpellInfoCorrections()
         spellInfo->AttributesEx4 |= SPELL_ATTR4_FIXED_DAMAGE;
     });
 
+    // Missile Barrage
+    ApplySpellFix({ 44401 }, [](SpellInfo* spellInfo)
+    {
+        // should be consumed before Clearcasting
+        spellInfo->Priority = 100;
+    });
+
     // Howl of Azgalor
     ApplySpellFix({ 31344 }, [](SpellInfo* spellInfo)
     {