patch 8.0.0455: the mode test may hang

Problem:    The mode test may hang in Test_mode(). (Michael Soyka)
Solution:   Set 'complete' to only search the current buffer (as suggested by
            Michael)
diff --git a/src/version.c b/src/version.c
index 2f9c315..aa40ae1 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    455,
+/**/
     454,
 /**/
     453,