patch 8.2.5121: interrupt test sometimes fails

Problem:    Interrupt test sometimes fails.
Solution:   Use a different file name.
diff --git a/src/version.c b/src/version.c
index df9d576..89e1fa1 100644
--- a/src/version.c
+++ b/src/version.c
@@ -735,6 +735,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    5121,
+/**/
     5120,
 /**/
     5119,