patch 8.2.4850: mksession mixes up "tabpages" and "curdir" arguments

Problem:    Mksession mixes up "tabpages" and "curdir" arguments.
Solution:   Correct logic for storing tabpage in session. (closes #10312)
diff --git a/src/version.c b/src/version.c
index 961016c..0e08c29 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4850,
+/**/
     4849,
 /**/
     4848,