patch 8.2.2154: popupwin test for terminal buffer fails sometimes

Problem:    Popupwin test for terminal buffer fails sometimes.
Solution:   Wait for the prompt to appear.
diff --git a/src/version.c b/src/version.c
index 2bb336e..bd2fd5d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2154,
+/**/
     2153,
 /**/
     2152,