tools: Use platform abstraction for I/O.
* tools/gpg-connect-agent.c (main): Use a gpgrt_stream_t for 'script_fp'. Adapt accordingly.
Werner asked me to make gpgconf use the platform abstractions that
were introduced after gpgconf's inception. After doing that, I
realized that 'read_line' is only used in two more places, one of
which this patch takes care of.
- Signed-off-by: Justus Winter <justus@g10code.com>