patch 8.2.3530: ":buf \{a}" fails while ":edit \{a}" works

Problem:    ":buf \{a}" fails while ":edit \{a}" works.
Solution:   Unescape "\{". (closes #8917)
diff --git a/src/session.c b/src/session.c
index 03b57f0..d2b360d 100644
--- a/src/session.c
+++ b/src/session.c
@@ -43,7 +43,7 @@
     }
 
     // escape special characters
-    p = vim_strsave_fnameescape(sname, FALSE);
+    p = vim_strsave_fnameescape(sname, VSE_NONE);
     vim_free(sname);
     if (p == NULL)
 	return FAIL;