patch 8.2.1086: possibly using freed memory when text properties used

Problem:    Possibly using freed memory when text properties used when
            changing indent of a line.
Solution:   Compute the offset before calling ml_replace().

src/version.c

@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1086,
 /**/
     1085,
 /**/