patch 8.2.3385: escaping for fish shell does not work properly

Problem:    Escaping for fish shell does not work properly.
Solution:   Insert a backslash before a backslash. (Jason Cox, closes #8810)
diff --git a/src/version.c b/src/version.c
index d50d098..5f427a8 100644
--- a/src/version.c
+++ b/src/version.c
@@ -756,6 +756,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3385,
+/**/
     3384,
 /**/
     3383,