patch 8.2.4437: vartabs test fails on MS-Windows

Problem:    Vartabs test fails on MS-Windows.
Solution:   Use iso8859-1 'encoding'. (Ken Takata, closes #9818)
diff --git a/src/testdir/test_vartabs.vim b/src/testdir/test_vartabs.vim
index d21acfe..74b07ba 100644
--- a/src/testdir/test_vartabs.vim
+++ b/src/testdir/test_vartabs.vim
@@ -445,10 +445,10 @@
 func Test_vartabstop_latin1()
   let save_encoding = &encoding
   new
-  set encoding=iso8859
-  silent norm :se 
+  set encoding=iso8859-1
+  silent exe "norm :se \<C-A>\<C-C>"
   set vartabstop=400
-  norm i00	
+  exe "norm i00\t\<C-D>"
   bwipe!
   let &encoding = save_encoding
 endfunc
diff --git a/src/version.c b/src/version.c
index 6eae5e6..7001029 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4437,
+/**/
     4436,
 /**/
     4435,