patch 8.1.1168: not all screen update code of terminal is executed in tests

Problem:    Not all screen update code of the terminal window is executed in
            tests.
Solution:   Redraw before taking a screenshot.
diff --git a/src/testdir/screendump.vim b/src/testdir/screendump.vim
index 4015419..1630dfa 100644
--- a/src/testdir/screendump.vim
+++ b/src/testdir/screendump.vim
@@ -113,6 +113,10 @@
   let reference = 'dumps/' . a:filename . '.dump'
   let testfile = 'failed/' . a:filename . '.dump'
 
+  " Redraw to execut the code that updates the screen.  Otherwise we get the
+  " text and attributes only from the internal buffer.
+  redraw
+
   let did_mkdir = 0
   if !isdirectory('failed')
     let did_mkdir = 1
diff --git a/src/version.c b/src/version.c
index a12bd09..99ffbc3 100644
--- a/src/version.c
+++ b/src/version.c
@@ -772,6 +772,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1168,
+/**/
     1167,
 /**/
     1166,