Merge pull request #21554 from craig-osterhout/samples-postgress

samples: fix postgres alias

Author: thaJeztah

content/reference/samples/postgres.md

@@ -5,5 +5,5 @@ service: postgresql
 aliases:
 - /engine/examples/postgresql_service/
 - /samples/postgresql_service/
-- /samples/postgresql/
+- /samples/postgres/
 ---