patch 8.0.0933: terminal test tries to start GUI when it's not possible

Problem:    Terminal test tries to start GUI when it's not possible.
Solution:   Check if the GUI can run. (James McCoy, closes #1971)
diff --git a/src/version.c b/src/version.c
index 850be59..ab8c314 100644
--- a/src/version.c
+++ b/src/version.c
@@ -770,6 +770,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    933,
+/**/
     932,
 /**/
     931,