utils: fix wrong filename in error message (#8643)

server/util.go

@@ -210,7 +210,7 @@ func interceptConfigs(rootViper *viper.Viper) (*tmcfg.Config, error) {
 		rootViper.SetConfigName("config")
 		rootViper.AddConfigPath(configPath)
 		if err := rootViper.ReadInConfig(); err != nil {
-			return nil, fmt.Errorf("failed to read in app.toml: %w", err)
+			return nil, fmt.Errorf("failed to read in config.toml: %w", err)
 		}
 	}