MM-10020: avoid duplicating unique indexes (#8587)

* unit test TestGet(Search)Replica

This adds partial, testing-focused support for SQLite, as well as removing
some translated log messages that required initializing i18n just for
testing.

* avoid returning master twice when no replicas are configured

* remove duplicate indexes

* unit test GetAllConns

store/sqlstore/upgrade.go

@@ -87,7 +87,7 @@ func UpgradeDatabase(sqlStore SqlStore) {
 			os.Exit(EXIT_VERSION_SAVE_MISSING)
 		}
 
-		l4g.Info(utils.T("store.sql.schema_set.info"), model.CurrentVersion)
+		l4g.Info("The database schema has been set to version %v", model.CurrentVersion)
 	}
 
 	// If we're not on the current version then it's too old to be upgraded
@@ -415,6 +415,10 @@ func UpgradeDatabaseToVersion410(sqlStore SqlStore) {
 	// TODO: Uncomment following condition when version 4.10.0 is released
 	//if shouldPerformUpgrade(sqlStore, VERSION_4_9_0, VERSION_4_10_0) {
 
+	sqlStore.RemoveIndexIfExists("Name_2", "Channels")
+	sqlStore.RemoveIndexIfExists("Name_2", "Emoji")
+	sqlStore.RemoveIndexIfExists("ClientId_2", "OAuthAccessData")
+
 	//	saveSchemaVersion(sqlStore, VERSION_4_10_0)
 	//}
 }