[LyX/master] Fix warnings

[Richard Kimberly Heck]

commit 6942dc9fb4ab38a73d73bf387c98a67abe22292c
Author: Richard Kimberly Heck <rikiheck at lyx.org>
Date:   Tue May 19 17:08:11 2020 -0400

    Fix warnings
---
 src/graphics/PreviewLoader.cpp |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/src/graphics/PreviewLoader.cpp b/src/graphics/PreviewLoader.cpp
index 1a9373a..d73e353 100644
--- a/src/graphics/PreviewLoader.cpp
+++ b/src/graphics/PreviewLoader.cpp
@@ -229,12 +229,13 @@ private:
 	///
 	QTimer * delay_refresh_;
 	///
+	Trackable trackable_;
+	///
 	bool finished_generating_;
 
 	/// We don't own this
 	static lyx::Converter const * pconverter_;
 
-	Trackable trackable_;
 };
 
 
@@ -452,6 +453,7 @@ PreviewLoader::Impl::preview(string const & latex_snippet) const
 	// Don't try to access the cache until we are done.
 	if (delay_refresh_->isActive() || !finished_generating_)
 		return nullptr;
+
 	Cache::const_iterator it = cache_.find(latex_snippet);
 	return (it == cache_.end()) ? nullptr : it->second.get();
 }