[LyX/master] Make string parameter a const reference

[Jean-Marc Lasgouttes]

commit 9b3c28178cf8835213e9da418dc66208a9afd6cd
Author: Jean-Marc Lasgouttes <lasgouttes at lyx.org>
Date:   Fri Sep 13 10:27:24 2024 +0200

    Make string parameter a const reference
    
    Spotted by Coverity scan.
---
 src/frontends/qt/GuiDelimiter.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/frontends/qt/GuiDelimiter.cpp b/src/frontends/qt/GuiDelimiter.cpp
index 479db87033..3d064288f5 100644
--- a/src/frontends/qt/GuiDelimiter.cpp
+++ b/src/frontends/qt/GuiDelimiter.cpp
@@ -82,7 +82,7 @@ static docstring fix_name(string const & str, bool big)
 }
 
 struct MathSymbol {
-	MathSymbol(char_type uc = '?', string icon = string())
+	MathSymbol(char_type uc = '?', string const & icon = string())
 		: unicode(uc), icon(icon)
 	{}
 	char_type unicode;