patch 9.1.0470: tests: Test_ColonEight_MultiByte() fails sporadically

Problem:  tests: Test_ColonEight_MultiByte() fails on MS-Windows
Solution: mark test as flaky

This single line change should have happened as part of v9.1.469 (and I
mentioned it in the Commit message), but forgot to actually include the
change :facepalm

Signed-off-by: Christian Brabandt <cb@256bit.org>

src/testdir/test_shortpathname.vim

@@ -78,6 +78,7 @@ func Test_ColonEight()
 endfunc
 
 func Test_ColonEight_MultiByte()
+  let g:test_is_flaky = 1
   let dir = 'Xtest'
 
   let file = dir . '/日本語のファイル.txt'

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    470,
 /**/
     469,
 /**/