Fix strncpy usage in botlib

All usage of strncpy in botlib should now either set string
terminator or use Q_strncpyz.

code/botlib/l_log.c

@@ -75,7 +75,7 @@ void Log_Open(char *filename)
 		botimport.Print(PRT_ERROR, "can't open the log file %s\n", filename);
 		return;
 	} //end if
-	strncpy(logfile.filename, filename, MAX_LOGFILENAMESIZE);
+	Q_strncpyz(logfile.filename, filename, MAX_LOGFILENAMESIZE);
 	botimport.Print(PRT_MESSAGE, "Opened log %s\n", logfile.filename);
 } //end of the function Log_Create
 //===========================================================================