[#18592] DocDB: Fix log message format in WritePostgresConfig

Summary:
WritePostgresConfig function uses %s in the format string instead of $0.

Fixes #18592
Jira: DB-7523

Test Plan: All jenkins tests

Reviewers: dsrinivasan

Reviewed By: dsrinivasan

Subscribers: yql, ybase

Differential Revision: https://phorge.dev.yugabyte.com/D27599

src/yb/yql/pgwrapper/pg_wrapper.cc

@@ -383,7 +383,7 @@ Result<string> WritePostgresConfig(const PgProcessConf& conf) {
   if (!conf_file) {
     return STATUS_FORMAT(
         IOError,
-        "Failed to read default postgres configuration '%s': errno=$0: $1",
+        "Failed to read default postgres configuration '$0': errno=$1: $2",
         default_conf_path,
         errno,
         ErrnoToString(errno));