[LyX/master] Guard new code for builds with OS X 10.11 SDK and lesser (part 2).

[Stephan Witt]

commit df990b1027bfc87f945e1ce29646bd874c5837fa
Author: Stephan Witt <switt at lyx.org>
Date:   Sat Jan 1 18:47:57 2022 +0100

    Guard new code for builds with OS X 10.11 SDK and lesser (part 2).
---
 src/support/AppleSupport.m |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/src/support/AppleSupport.m b/src/support/AppleSupport.m
index 3a4f864..2c78bd2 100644
--- a/src/support/AppleSupport.m
+++ b/src/support/AppleSupport.m
@@ -42,6 +42,10 @@ void appleCleanupViewMenu() {
 
 
 bool appleUserTabbingPreferenceAlways() {
+#if defined(__MAC_OS_X_VERSION_MAX_ALLOWED) && (__MAC_OS_X_VERSION_MAX_ALLOWED >= 101200)
 	return [NSWindow respondsToSelector:@selector(userTabbingPreference)] &&
 		[NSWindow userTabbingPreference] == NSWindowUserTabbingPreferenceAlways;
+#else
+	return false;
+#endif
 }