[LyX/master] Fix warning

[Richard Kimberly Heck]

commit b28bd27932c671963cc79013ade44f0513d57ca8
Author: Richard Kimberly Heck <rikiheck at lyx.org>
Date:   Sat Oct 10 10:00:16 2020 -0400

    Fix warning
---
 src/KeyMap.cpp |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/src/KeyMap.cpp b/src/KeyMap.cpp
index c5c387f..3698ddb 100644
--- a/src/KeyMap.cpp
+++ b/src/KeyMap.cpp
@@ -299,7 +299,7 @@ KeyMap::ReturnValues KeyMap::readWithoutConv(FileName const & bind_file, KeyMap
 	LYXERR(Debug::KBMAP, "Reading bind file:" << bind_file.absFileName());
 
 	// format of pre-2.0 bind files, before this tag was introduced.
-	unsigned int format = 0;
+	int format = 0;
 	bool error = false;
 	while (lexrc.isOK()) {
 		switch (lexrc.lex()) {