patch 8.0.1578: no test for :popup in terminal

Problem:    No test for :popup in terminal.
Solution:   Add a screen dump test.
diff --git a/src/version.c b/src/version.c
index 8cc867f..a6f9abd 100644
--- a/src/version.c
+++ b/src/version.c
@@ -767,6 +767,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1578,
+/**/
     1577,
 /**/
     1576,