[LyX/master] Amend 8e0bc01d

[Thibaut Cuvelier]

commit 27c01ee1d37e979f044329bcf07b9e910ed2b7ad
Author: Thibaut Cuvelier <tcuvelier at lyx.org>
Date:   Tue Feb 27 00:45:10 2024 +0100

    Amend 8e0bc01d
    
    std::set::find only appeared in C++20. Rather use std::set::find for compatibility.
---
 src/insets/InsetBibtex.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/insets/InsetBibtex.cpp b/src/insets/InsetBibtex.cpp
index 8a2a697648..2e6f7f7fb7 100644
--- a/src/insets/InsetBibtex.cpp
+++ b/src/insets/InsetBibtex.cpp
@@ -1220,7 +1220,7 @@ void InsetBibtex::docbook(XMLStream & xs, OutputParams const &) const
 				if (docbookTag == "SPECIFIC") {
 					delayedTags[match[1]] = match[2];
 				} else {
-					if (alreadyOutputDocBookTags.contains(docbookTag)) {
+					if (alreadyOutputDocBookTags.find(docbookTag) != alreadyOutputDocBookTags.end()) {
 						xs << XMLStream::ESCAPE_NONE <<
 						   from_utf8("<!-- Several similar tags in the reference for ") + from_utf8(docbookTag) +
 						   from_utf8(". New tag: ") + from_utf8(match[1]) + from_utf8(". Corresponding value: ") +