patch 9.1.0046: :drop does not re-use empty buffer

Problem:  :drop does not re-use empty buffer
          (Rocco Mao)
Solution: Make :drop re-use an empty buffer
          (Rocco Mao)

fixes: #13851
closes: #13881

Signed-off-by: Rocco Mao <dapeng.mao@qq.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index 9254512..ccfcb16 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    46,
+/**/
     45,
 /**/
     44,