AK: Use operator== for comparison in Vector::contains_slow

Author: https://github.com/rburchell
Commit: bee39d8524
Pull-request: https://github.com/SerenityOS/serenity/pull/294

AK/Vector.h

@@ -168,7 +168,7 @@ public:
     bool contains_slow(const T& value) const
     {
         for (int i = 0; i < size(); ++i) {
-            if (Traits<T>::equals(at(i), value))
+            if (at(i) == value)
                 return true;
         }
         return false;