patch 8.0.0857: terminal test fails on MS-Windows

Problem:    Terminal test fails on MS-Windows.
Solution:   Sleep a fraction of a second.
diff --git a/src/testdir/test_terminal.vim b/src/testdir/test_terminal.vim
index 987b1ee..3f5e268 100644
--- a/src/testdir/test_terminal.vim
+++ b/src/testdir/test_terminal.vim
@@ -152,6 +152,10 @@
   call term_wait(1234)
 
   call term_wait(buf)
+  if has('win32')
+    " TODO: this should not be needed
+    sleep 100m
+  endif
   call Check_123(buf)
 
   " Must still work after the job ended.
diff --git a/src/version.c b/src/version.c
index b8d0203..1c01f4f 100644
--- a/src/version.c
+++ b/src/version.c
@@ -770,6 +770,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    857,
+/**/
     856,
 /**/
     855,