patch 8.2.3611: crash when using CTRL-W f without finding a file name

Problem:    Crash when using CTRL-W f without finding a file name.
Solution:   Bail out when the file name length is zero.
diff --git a/src/version.c b/src/version.c
index d301120..4251b03 100644
--- a/src/version.c
+++ b/src/version.c
@@ -758,6 +758,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3611,
+/**/
     3610,
 /**/
     3609,