patch 8.0.1588: popup menu hangs after typing CTRL-C

Problem:    Popup menu hangs after typing CTRL-C.
Solution:   Make CTRL-C exit the loop. (Ozaki Kiichi, closes #2697)
diff --git a/src/version.c b/src/version.c
index 8cfc17c..8bbd1e4 100644
--- a/src/version.c
+++ b/src/version.c
@@ -767,6 +767,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1588,
+/**/
     1587,
 /**/
     1586,