RawReadString is limited to length of shortstring, don't read more than that

packages/rtl-console/src/unix/keyboard.pp

@@ -1819,6 +1819,7 @@ begin
        ch:=#0;
      if ch<>#0 then
        St:=St+ch;
+     if length(st)=255 then break;
   Until ch=#0;
   RawReadString:=St;
 end;