patch 8.2.2804: setting buffer local mapping with mapset() changes global

Problem:    Setting buffer local mapping with mapset() changes global mapping.
Solution:   Only set the local mapping. (closes #8143)
diff --git a/src/version.c b/src/version.c
index a6667e9..c5c3fee 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2804,
+/**/
     2803,
 /**/
     2802,