sql update postgres needs type PG_BYTEA

The parameter "data" needs to be binded explicitely as type DBD::PG::PG_BYTEA in
order to be properly escaped:

http://search.cpan.org/~rudy/DBD-Pg/Pg.pm
https://rt.cpan.org/Public/Bug/Display.html?id=13180

If not, this error occurs:
```
DBD::Pg::st execute failed: ERROR:  invalid input syntax for type bytea
```