fix segfault during bb quest loading

src/CommandFormats.hh

@@ -566,7 +566,7 @@ struct S_GuildCardSearchResult_BB_41 : S_GuildCardSearchResult<PSOCommandHeaderB
 
 struct S_OpenFile_PC_GC_44_A6 {
   ptext<char, 0x20> name;
-  le_uint16_t unused;
+  parray<uint8_t, 2> unused;
   le_uint16_t flags; // 0 = download quest, 2 = online quest, 3 = Episode 3
   ptext<char, 0x10> filename;
   le_uint32_t file_size;

src/SendCommands.cc

@@ -1375,7 +1375,7 @@ void send_quest_open_file_t(
     default:
       throw logic_error("invalid quest file type");
   }
-  cmd.unused = 0;
+  cmd.unused.clear();
   cmd.file_size = file_size;
   cmd.filename = filename.c_str();
   send_command_t(c, command_num, 0x00, cmd);