patch 8.2.4819: unmapping simplified keys also deletes other mapping

Problem:    Unmapping simplified keys also deletes other mapping.
Solution:   Only unmap a mapping with m_simplified set. (closes #10270)
diff --git a/src/version.c b/src/version.c
index 74b4625..1d54137 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4819,
+/**/
     4818,
 /**/
     4817,