patch 8.0.0955: Test_existent_file() fails on some file systems

Problem:    Test_existent_file() fails on some file systems.
Solution:   Run the test again with a sleep when the test fails without a
            sleep. (James McCoy, closes #1984)
diff --git a/src/version.c b/src/version.c
index 0990d83..9859b4a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -770,6 +770,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    955,
+/**/
     954,
 /**/
     953,