Feature request: ripe_diff/ripe_import: Use conninfo from configuration by default

[sebix]

The executables ripe_import and ripe_diff require the parameter --conninfo.

It would be user-friendlier to take the default conninfo from /etc/intelmq/eventdb-serve.conf which usually holds a connection info with write permission to the tables.

That also prevents the password is in the command line and thus visible to other processes and recorded in the shell's history.