pg_dump - foreign table - server name is not quoted

Hello.

I noticed what I think is a bug in pg_dump.

When dumping foreign tables, the server name is not properly quoted,
which leads to unrestorable dumps.

eg, a foreign table attached to a foreign server named "file-test" is
dumped as:

CREATE FOREIGN TABLE "test-table" (
    col1 integer
)
SERVER file-test
OPTIONS (filename '/tmp/test');


Please look at the attached test case and the proposed patch.

Thank you.

--
Ronan Dunklau