patch 8.1.0957: Mac: fsync fails on network share

Problem:    Mac: fsync fails on network share.
Solution:   Check for ENOTSUP. (Yee Cheng Chin, closes #4016)
diff --git a/src/version.c b/src/version.c
index b705463..5a3a53c 100644
--- a/src/version.c
+++ b/src/version.c
@@ -780,6 +780,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    957,
+/**/
     956,
 /**/
     955,