pg_restore syntax missing SSL flags

Problem is on following page:

http://docs.citusdata.com/en/v7.5/develop/migration_data_small.html

pg_restore syntax is missing SSL mode required to connect to Citus Cloud or be secure in general. 2 suggested ways of fixing this:

1. Change syntax to use -d flag like this:

`pg_restore -d postgres://user:password@hostname:5432?sslmode=require outputfile.dump`

2. Set PGSSLMODE environment variable as follows:

```
PGSSLMODE=require pg_restore \
--host=host \
--dbname=dbname \
--username=username \
data.dump
```