added postgrest-docs-linkcheck; clean up links

* removed outdated links
* updated permanent redirections
* updated postgres docs links to current version
* sort links in ecosystems by repo-name
* change http:// to https://

admin.rst

@@ -1,3 +1,5 @@
+.. _admin:
+
 Hardening PostgREST
 ===================
 
@@ -51,7 +53,7 @@ However it's very easy to delete the **entire table** by omitting the query para
 
   DELETE /logs HTTP/1.1
 
-This can happen accidentally such as by switching a request from a GET to a DELETE. To protect against accidental operations use the `pg-safeupdate <https://github.com/eradman/pg-safeupdate>`_ PostgreSQL extension. It raises an error if UPDATE or DELETE are executed without specifying conditions. To install it you can use the `PGXN <http://pgxn.org/>`_ network:
+This can happen accidentally such as by switching a request from a GET to a DELETE. To protect against accidental operations use the `pg-safeupdate <https://github.com/eradman/pg-safeupdate>`_ PostgreSQL extension. It raises an error if UPDATE or DELETE are executed without specifying conditions. To install it you can use the `PGXN <https://pgxn.org/>`_ network:
 
 .. code-block:: bash
 
@@ -60,7 +62,7 @@ This can happen accidentally such as by switching a request from a GET to a DELE
   # then add this to postgresql.conf:
   # shared_preload_libraries='safeupdate';
 
-This does not protect against malicious actions, since someone can add a url parameter that does not affect the result set. To prevent this you must turn to database permissions, forbidding the wrong people from deleting rows, and using `row-level security <https://www.postgresql.org/docs/current/static/ddl-rowsecurity.html>`_ if finer access control is required.
+This does not protect against malicious actions, since someone can add a url parameter that does not affect the result set. To prevent this you must turn to database permissions, forbidding the wrong people from deleting rows, and using `row-level security <https://www.postgresql.org/docs/current/ddl-rowsecurity.html>`_ if finer access control is required.
 
 Count-Header DoS
 ----------------