[LyX/2.3.x] Fix bug #11864

[Richard Kimberly Heck]

commit 94c2466c4c5db069742aa2441c247d66d82903f8
Author: Richard Kimberly Heck <rikiheck at lyx.org>
Date:   Wed May 13 14:44:03 2020 -0400

    Fix bug #11864
---
 src/insets/ExternalTemplate.cpp |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/src/insets/ExternalTemplate.cpp b/src/insets/ExternalTemplate.cpp
index ae9148b..39a96ae 100644
--- a/src/insets/ExternalTemplate.cpp
+++ b/src/insets/ExternalTemplate.cpp
@@ -22,6 +22,7 @@
 #include "support/PathChanger.h"
 #include "support/Translator.h"
 
+#include <algorithm>
 #include <ostream>
 
 using namespace std;