Fix strncpy usage in botlib

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

code/botlib/l_struct.c

@@ -221,7 +221,7 @@ int ReadString(source_t *source, fielddef_t *fd, void *p)
 	//remove the double quotes
 	StripDoubleQuotes(token.string);
 	//copy the string
-	strncpy((char *) p, token.string, MAX_STRINGFIELD);
+	strncpy((char *) p, token.string, MAX_STRINGFIELD-1);
 	//make sure the string is closed with a zero
 	((char *)p)[MAX_STRINGFIELD-1] = '\0';
 	//