[LyX/master] Fixup b0c102cfb: make it possible to select medskip as parskip

[Jean-Marc Lasgouttes]

commit 5c055034c2076160bcb6ea7ae6d42de694cc2ca7
Author: Jean-Marc Lasgouttes <lasgouttes at lyx.org>
Date:   Fri Oct 29 16:38:29 2021 +0200

    Fixup b0c102cfb: make it possible to select medskip as parskip
    
    Some new parskip possibilities had been added, but the check for
    custom length index had not bee updated.
    
    This code is very fragile.
    
    Related to bug #10968.
---
 src/frontends/qt/GuiDocument.cpp |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/src/frontends/qt/GuiDocument.cpp b/src/frontends/qt/GuiDocument.cpp
index 5a4584e..ee2ee17 100644
--- a/src/frontends/qt/GuiDocument.cpp
+++ b/src/frontends/qt/GuiDocument.cpp
@@ -4861,7 +4861,7 @@ bool GuiDocument::isValid()
 			// if we're asking for skips between paragraphs
 			!textLayoutModule->skipRB->isChecked() ||
 			// then either we haven't chosen custom
-			textLayoutModule->skipCO->currentIndex() != 3 ||
+			textLayoutModule->skipCO->currentIndex() != 5 ||
 			// or else a length has been given
 			!textLayoutModule->skipLE->text().isEmpty()
 		) &&