[LyX/master] Don't add LabelString for Manual LabelType

[Jean-Marc Lasgouttes]

commit 975115479a69aa6026a5b922acc1c7b94bdd0be1
Author: Daniel Ramoeller <d.lyx at web.de>
Date:   Thu Apr 20 23:49:46 2023 +0200

    Don't add LabelString for Manual LabelType
    
    Fix for bug  #12753
---
 src/Paragraph.cpp |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/src/Paragraph.cpp b/src/Paragraph.cpp
index 5487b80..025acf1 100644
--- a/src/Paragraph.cpp
+++ b/src/Paragraph.cpp
@@ -4299,6 +4299,7 @@ docstring Paragraph::asString(pos_type beg, pos_type end, int options, const Out
 
 	if (beg == 0
 	    && options & AS_STR_LABEL
+	    && d->layout_->labeltype != LABEL_MANUAL
 	    && !d->params_.labelString().empty())
 		os << d->params_.labelString() << ' ';