Wow, I never realized this before o.o
Than you, I'll fix it in my next commit on this branch.

Btw, this is where the tab is from:

```
$ grep -R ifndef\\t src
src/common/console.h:#ifndef    _COMMON_CONSOLE_H_
src/common/core.h:#ifndef       _COMMON_CORE_H_
src/common/des.h:#ifndef        _COMMON_DES_H_
src/common/grfio.h:#ifndef      _COMMON_GRFIO_H_
src/common/HPM.h:#ifndef        _COMMON_HPM_H_
src/common/HPMi.h:#ifndef       _COMMON_HPMI_H_
src/common/mmo.h:#ifndef        _COMMON_MMO_H_
src/common/socket.h:#ifndef     _COMMON_SOCKET_H_
src/common/sysinfo.h:#ifndef    _COMMON_SYSINFO_H_
src/common/timer.h:#ifndef      _COMMON_TIMER_H_
src/map/trade.h:#ifndef _MAP_TRADE_H_
src/map/vending.h:#ifndef       _MAP_VENDING_H_
```