fix a buffer overlap with newer mac osx strlcpy

fix a buffer overlap with newer mac osx strlcpy

this fails on strcpy overlap detection in newer Mac OSX releases.

Error report: Mac OS X 10.10 (14A389)

Crashed Thread:        0  Dispatch queue: com.apple.main-thread

Exception Type:        EXC_CRASH (SIGABRT)
Exception Codes:       0x0000000000000000, 0x0000000000000000

Application Specific Information:
detected source and destination buffer overlap

Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0   libsystem_kernel.dylib        	0x00007fff91017282 __pthread_kill + 10
1   libsystem_c.dylib             	0x00007fff922aab73 abort + 129
2   libsystem_c.dylib             	0x00007fff922aacea abort_report_np + 181
3   libsystem_c.dylib             	0x00007fff922d0dd0 __chk_fail + 48
4   libsystem_c.dylib             	0x00007fff922d0de0 __chk_fail_overlap + 16
5   libsystem_c.dylib             	0x00007fff922d0e11 __chk_overlap + 49
6   libsystem_c.dylib             	0x00007fff922d0e7e __strlcpy_chk + 68
7   darkplaces-sdl                	0x0000000104a3a29a Mod_LoadTextureFromQ3Shader + 74 (model_shared.c:2446)
8   darkplaces-sdl                	0x0000000104a21010 Mod_Q3BSP_Load + 2224 (model_brush.c:5134)
9   darkplaces-sdl                	0x0000000104a1e265 Mod_IBSP_Load + 85 (model_brush.c:7956)
10  darkplaces-sdl                	0x0000000104a3398b Mod_LoadModel + 1419 (model_shared.c:498)
11  darkplaces-sdl                	0x0000000104a37717 Mod_ForName + 55 (model_shared.c:616)
12  darkplaces-sdl                	0x0000000104ad3f28 SV_SpawnServer + 424 (sv_main.c:3284)
13  darkplaces-sdl                	0x00000001049e497f Host_Map_f + 319 (host_cmd.c:394)
14  darkplaces-sdl                	0x00000001049e4bad Host_Changelevel_f + 221 (host_cmd.c:416)
15  darkplaces-sdl                	0x000000010494d6f9 Cmd_ExecuteString + 617 (cmd.c:1936)
16  darkplaces-sdl                	0x000000010494d14d Cbuf_Execute + 781 (cmd.c:368)
17  darkplaces-sdl                	0x000000010494dbd5 Cbuf_Frame + 597 (cmd.c:384)
18  darkplaces-sdl                	0x00000001049e0109 Host_Main + 1305 (host.c:781)
19  darkplaces-sdl                	0x00000001048c2f06 main + 166 (sys_sdl.c:223)
20  libdyld.dylib                 	0x00007fff8e7735c9 start + 1

From: nyov <nyov@nexnode.net>

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@12103 d7cf8633-e32d-0410-b094-e92efae38249
::stable-branch::merge=8f317e4b0e366bff1ba380af77279c3d16d588e9