[LyX/master] Clean math headers

[Yuriy Skalko]

commit a3eeb8a4b5d8285db88a3bed02eaebc5fc4ec515
Author: Yuriy Skalko <yuriy.skalko at gmail.com>
Date:   Thu Oct 15 12:00:48 2020 +0300

    Clean math headers
---
 src/mathed/MathRow.h    |    3 +--
 src/mathed/MathStream.h |    1 -
 2 files changed, 1 insertions(+), 3 deletions(-)

diff --git a/src/mathed/MathRow.h b/src/mathed/MathRow.h
index f2b0445..d985569 100644
--- a/src/mathed/MathRow.h
+++ b/src/mathed/MathRow.h
@@ -26,11 +26,10 @@ namespace lyx {
 
 class BufferView;
 class Dimension;
+class MathData;
 class MetricsInfo;
 class PainterInfo;
 
-class InsetMath;
-class MathData;
 
 /*
  * While for editing purpose it is important that macros are counted
diff --git a/src/mathed/MathStream.h b/src/mathed/MathStream.h
index 1d7e1de..db4a499 100644
--- a/src/mathed/MathStream.h
+++ b/src/mathed/MathStream.h
@@ -25,7 +25,6 @@
 namespace lyx {
 
 class Encoding;
-class InsetMath;
 class MathAtom;
 class MathData;