[LyX/master] Fix warning.

[Jean-Marc Lasgouttes]

commit b3890d9eab40f996061f8ae1a7353b6819cd9774
Author: Jean-Marc Lasgouttes <lasgouttes at lyx.org>
Date:   Fri Sep 24 18:45:08 2021 +0200

    Fix warning.
---
 src/frontends/qt/GuiFontMetrics.h |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)

diff --git a/src/frontends/qt/GuiFontMetrics.h b/src/frontends/qt/GuiFontMetrics.h
index 95b577c..9c7ce89 100644
--- a/src/frontends/qt/GuiFontMetrics.h
+++ b/src/frontends/qt/GuiFontMetrics.h
@@ -39,8 +39,6 @@ struct BreakAtKey
 	bool force;
 };
 
-static uint qHash(BreakAtKey const &);
-
 struct TextLayoutKey
 {
 	bool operator==(TextLayoutKey const & key) const {