[LyX/master] Allow listings insets to be edited externally.

[Richard Kimberly Heck]

commit aa39a2aaf7d2175bdcf423d3d3d22c93588c5c20
Author: Richard Kimberly Heck <rikiheck at lyx.org>
Date:   Sat Dec 5 21:17:02 2020 -0500

    Allow listings insets to be edited externally.
---
 lib/layouts/stdinsets.inc |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/lib/layouts/stdinsets.inc b/lib/layouts/stdinsets.inc
index 8ebf2c7..e4fec96 100644
--- a/lib/layouts/stdinsets.inc
+++ b/lib/layouts/stdinsets.inc
@@ -368,6 +368,7 @@ InsetLayout Listings
 	ForcePlain            true
 	NeedCProtect          true
 	RefPrefix             lst
+	EditExternal          true
 	HTMLTag               pre
 	HTMLStyle
 		div.float-listings {