fixes some more Mac OS X buffer overlap errors

fixes some more Mac OS X buffer overlap errors

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                	0x0000000102903b3e SV_UpdateToReliableMessages + 398 (sv_main.c:2480)
8   darkplaces-sdl                	0x00000001029038bb SV_SendClientMessages + 59 (sv_main.c:2575)
9   darkplaces-sdl                	0x000000010278bb5e Host_Main + 3758 (host.c:910)
10  darkplaces-sdl                	0x00000001025be64f main + 239 (sys_sdl.c:223)
11  libdyld.dylib                 	0x00007fff8e7735c9 start + 1

From: nyov <nyov@nexnode.net>

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@12104 d7cf8633-e32d-0410-b094-e92efae38249
::stable-branch::merge=a9a2f5f032331adc43ae3bf99118464157b807ab