Update to new Throw message.

src/PokemonAI.hpp

@@ -60,8 +60,7 @@ namespace PkmnLibAI {
                     return userIndex;
                 }
             }
-            THROW("Unknown attack target kind: '" << CreatureLib::Library::AttackTargetHelper::ToString(moveTarget)
-                                                  << "'.")
+            THROW("Unknown attack target kind: '", CreatureLib::Library::AttackTargetHelper::ToString(moveTarget), "'.")
         }
     };
 }