patch 8.0.0633: the client-server test is still a bit flaky

Problem:    The client-server test is still a bit flaky.
Solution:   Wait a bit for the GUI to start.  Check that the version number
            can be obtained.
diff --git a/src/version.c b/src/version.c
index 3c7c967..eb25404 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    633,
+/**/
     632,
 /**/
     631,