pgsql: Fix casting away const-ness in pg_restore.c

Fix casting away const-ness in pg_restore.c

This was intoduced in commit 763aaa06f03

per gripe from Peter Eistentrut.

Author: Mahendra Singh Thalor <mahi6run@gmail.com>

Slightly tweaked by me.

Discussion: https://postgr.es/m/016819c0-666e-42a8-bfc8-2b93fd8d0176@eisentraut.org

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/01c729e0c7a5899b841e596147381f5437ab8aab

Modified Files
--------------
src/bin/pg_dump/pg_restore.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)