Message style improvements

* Avoid pointlessly highlighting that an index vacuum was executed by a
  parallel worker; user doesn't care.

* Don't give the impression that a non-concurrent reindex of an invalid
  index on a TOAST table would work, because it wouldn't.

* Add a "translator:" comment for a mysterious message.

Discussion: https://postgr.es/m/20201107034943.GA16596@alvherre.pgsql
Reviewed-by: Michael Paquier <michael@paquier.xyz>

Author: alvherre

src/backend/access/heap/vacuumlazy.c

@@ -2407,7 +2407,6 @@ lazy_vacuum_index(Relation indrel, IndexBulkDeleteResult **stats,
 				  LVDeadTuples *dead_tuples, double reltuples, LVRelStats *vacrelstats)
 {
 	IndexVacuumInfo ivinfo;
-	const char *msg;
 	PGRUsage	ru0;
 	LVSavedErrInfo saved_err_info;
 
@@ -2437,13 +2436,8 @@ lazy_vacuum_index(Relation indrel, IndexBulkDeleteResult **stats,
 	*stats = index_bulk_delete(&ivinfo, *stats,
 							   lazy_tid_reaped, (void *) dead_tuples);
 
-	if (IsParallelWorker())
-		msg = gettext_noop("scanned index \"%s\" to remove %d row versions by parallel vacuum worker");
-	else
-		msg = gettext_noop("scanned index \"%s\" to remove %d row versions");
-
 	ereport(elevel,
-			(errmsg(msg,
+			(errmsg("scanned index \"%s\" to remove %d row versions",
 					vacrelstats->indname,
 					dead_tuples->num_tuples),
 			 errdetail_internal("%s", pg_rusage_show(&ru0))));
@@ -2466,7 +2460,6 @@ lazy_cleanup_index(Relation indrel,
 				   double reltuples, bool estimated_count, LVRelStats *vacrelstats)
 {
 	IndexVacuumInfo ivinfo;
-	const char *msg;
 	PGRUsage	ru0;
 	LVSavedErrInfo saved_err_info;
 
@@ -2497,13 +2490,8 @@ lazy_cleanup_index(Relation indrel,
 
 	if (*stats)
 	{
-		if (IsParallelWorker())
-			msg = gettext_noop("index \"%s\" now contains %.0f row versions in %u pages as reported by parallel vacuum worker");
-		else
-			msg = gettext_noop("index \"%s\" now contains %.0f row versions in %u pages");
-
 		ereport(elevel,
-				(errmsg(msg,
+				(errmsg("index \"%s\" now contains %.0f row versions in %u pages",
 						RelationGetRelationName(indrel),
 						(*stats)->num_index_tuples,
 						(*stats)->num_pages),

src/backend/commands/indexcmds.c

@@ -2993,13 +2993,14 @@ ReindexRelationConcurrently(Oid relationOid, int options)
 
 				/*
 				 * Don't allow reindex for an invalid index on TOAST table, as
-				 * if rebuilt it would not be possible to drop it.
+				 * if rebuilt it would not be possible to drop it.  Match
+				 * error message in reindex_index().
 				 */
 				if (IsToastNamespace(get_rel_namespace(relationOid)) &&
 					!get_index_isvalid(relationOid))
 					ereport(ERROR,
 							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-							 errmsg("cannot reindex invalid index on TOAST table concurrently")));
+							 errmsg("cannot reindex invalid index on TOAST table")));
 
 				/* Save the list of relation OIDs in private context */
 				oldcontext = MemoryContextSwitchTo(private_context);

src/backend/libpq/be-secure-openssl.c

@@ -181,6 +181,7 @@ be_tls_init(bool isServerStart)
 		if (ssl_ver_min == -1)
 		{
 			ereport(isServerStart ? FATAL : LOG,
+			/*- translator: first %s is a GUC option name, second %s is its value */
 					(errmsg("\"%s\" setting \"%s\" not supported by this build",
 							"ssl_min_protocol_version",
 							GetConfigOption("ssl_min_protocol_version",
@@ -203,6 +204,7 @@ be_tls_init(bool isServerStart)
 		if (ssl_ver_max == -1)
 		{
 			ereport(isServerStart ? FATAL : LOG,
+			/*- translator: first %s is a GUC option name, second %s is its value */
 					(errmsg("\"%s\" setting \"%s\" not supported by this build",
 							"ssl_max_protocol_version",
 							GetConfigOption("ssl_max_protocol_version",