patch 8.0.0993: sometimes an xterm sends an extra CTRL-X

Problem:    Sometimes an xterm sends an extra CTRL-X after the response for
            the background color.  Related to t_RS.
Solution:   Check for the CTRL-X after the terminating 0x7.
diff --git a/src/version.c b/src/version.c
index 1006ca0..e54b7bc 100644
--- a/src/version.c
+++ b/src/version.c
@@ -770,6 +770,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    993,
+/**/
     992,
 /**/
     991,