Fix console formatter for timestampunixnano (#502)

Co-authored-by: Ted Lilley <ted.lilley@digi.com>

console.go

@@ -348,15 +348,19 @@ func consoleDefaultFormatTimestamp(timeFormat string, noColor bool) Formatter {
 			if err != nil {
 				t = tt.String()
 			} else {
-				var sec, nsec int64 = i, 0
+				var sec, nsec int64
+
 				switch TimeFieldFormat {
-				case TimeFormatUnixMs:
-					nsec = int64(time.Duration(i) * time.Millisecond)
-					sec = 0
+				case TimeFormatUnixNano:
+					sec, nsec = 0, i
 				case TimeFormatUnixMicro:
-					nsec = int64(time.Duration(i) * time.Microsecond)
-					sec = 0
+					sec, nsec = 0, int64(time.Duration(i)*time.Microsecond)
+				case TimeFormatUnixMs:
+					sec, nsec = 0, int64(time.Duration(i)*time.Millisecond)
+				default:
+					sec, nsec = i, 0
 				}
+
 				ts := time.Unix(sec, nsec)
 				t = ts.Format(timeFormat)
 			}