Fix leading newlines after removing 'dumped by' and restrict lines

[Billiam]

If an SQL dump contains both dumped from/by comments and \restrict, the comments and double newlines are both removed before \restrict is removed, so this input:

\restrict eVA4gCZvdSnhJn7MKha0lZbmA4

-- Dumped from database version 17.4
-- Dumped by pg_dump version 17.6

SET statement_timeout = 0;
SET lock_timeout = 0;
SET idle_in_transaction_session_timeout = 0;

becomes:

SET statement_timeout = 0;
SET lock_timeout = 0;
SET idle_in_transaction_session_timeout = 0;

after cleanup.

To fix this, I'm trimming all newlines that follow the restrict, instead of limiting the replacement to 2 newline.