patch 8.0.0919: cursor color isn't set on startup

Problem:    Cursor color isn't set on startup.
Solution:   Initialize showing_mode to invalid value.
diff --git a/src/version.c b/src/version.c
index c3918a2..fa404b6 100644
--- a/src/version.c
+++ b/src/version.c
@@ -770,6 +770,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    919,
+/**/
     918,
 /**/
     917,