patch 7.4.1017
Problem:    When there is a backslash in an option ":set -=" doesn't work.
Solution:   Handle a backslash better. (Jacob Niehus)  Add a new test, merge
            in old test.
diff --git a/src/version.c b/src/version.c
index b491c48..dfb6ad1 100644
--- a/src/version.c
+++ b/src/version.c
@@ -742,6 +742,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1017,
+/**/
     1016,
 /**/
     1015,