bugfix: lib/sh/local.sh: public_schema_exists(): can no longer use psql_script_vegbien for this, because using `SET search_path` (called by psql_script_vegbien) with a schema that does not exist no longer produces an error. instead, use new pg_schema_exists(), which uses a different command that does produce an error if the schema does not exist.
bugfix: lib/sh/local.sh: public_schema_exists(): can no longer use psql_script_vegbien for this, because using `SET search_path` (called by psql_script_vegbien) with a schema that does not exist no longer produces an error. instead, use new pg_schema_exists(), which uses a different command that does produce an error if the schema does not exist.