patch 8.2.2776: :mksession uses current value of 'splitbelow' and 'splitright'

Problem:    :mksession uses current value of 'splitbelow' and 'splitright'
            even though "options" is not in 'sessionoptions'. (Maxim Kim)
Solution:   Save and restore the values, instead of setting to the current
            value. (closes #8119)
diff --git a/src/version.c b/src/version.c
index 3f3b2c9..e1f1526 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2776,
+/**/
     2775,
 /**/
     2774,