[LyX/master] Amend 9b1dc338b2. Fix compilation in GCC 4.9

[Yuriy Skalko]

commit 888ff9c114723c6578dcca4d10b041851d178fa4
Author: Yuriy Skalko <yuriy.skalko at gmail.com>
Date:   Sun Nov 15 22:36:22 2020 +0200

    Amend 9b1dc338b2. Fix compilation in GCC 4.9
---
 src/support/Changer.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/src/support/Changer.h b/src/support/Changer.h
index 19a6b9a..4c79052 100644
--- a/src/support/Changer.h
+++ b/src/support/Changer.h
@@ -73,7 +73,7 @@ inline Changer noChange()
 /// To apply the change conditionally, one can write:
 ///     Changer dummy = (cond) ? changeVar(ref, val) : noChange();
 template <typename X>
-inline Changer changeVar(X & ref, X const val)
+inline RefChanger<X> changeVar(X & ref, X const val)
 {
 	auto rc = make_save(ref);
 	ref = val;