patch 8.2.0853: ml_delete() often called with FALSE argument

Problem:    ml_delete() often called with FALSE argument.
Solution:   Use ml_delete_flags(x, ML_DEL_MESSAGE) when argument is TRUE.
diff --git a/src/evalbuffer.c b/src/evalbuffer.c
index adbbca3..df5270a 100644
--- a/src/evalbuffer.c
+++ b/src/evalbuffer.c
@@ -513,7 +513,7 @@
     }
 
     for (lnum = first; lnum <= last; ++lnum)
-	ml_delete(first, TRUE);
+	ml_delete_flags(first, ML_DEL_MESSAGE);
 
     FOR_ALL_TAB_WINDOWS(tp, wp)
 	if (wp->w_buffer == buf)