patch 8.1.1671: copying a blob may result in it being locked

Problem:    Copying a blob may result in it being locked.
Solution:   Reset v_lock. (Ken Takata, closes #4648)
diff --git a/src/version.c b/src/version.c
index b5504b1..9825924 100644
--- a/src/version.c
+++ b/src/version.c
@@ -778,6 +778,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1671,
+/**/
     1670,
 /**/
     1669,