[LyX/master] Remove useless declaration

[Yuriy Skalko]

commit cbd1b3a2d47b34d81b7c8e63ffbddadac4c32d7f
Author: Yuriy Skalko <yuriy.skalko at gmail.com>
Date:   Tue Dec 15 09:25:28 2020 +0200

    Remove useless declaration
---
 src/support/Timeout.h |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)

diff --git a/src/support/Timeout.h b/src/support/Timeout.h
index eef78db..cf15a58 100644
--- a/src/support/Timeout.h
+++ b/src/support/Timeout.h
@@ -55,8 +55,6 @@ private:
 	///
 	class Impl;
 	///
-	friend class Impl;
-	///
 	Impl * const pimpl_;
 	/// one-shot or repeating
 	Type type;