patch 8.1.2061: MS-Windows GUI: ":sh" crashes when trying to use a terminal

Problem:    MS-Windows GUI: ":sh" crashes when trying to use a terminal.
Solution:   Check for a NULL command. (Yasuhiro Matsumoto, closes #4958)
diff --git a/src/version.c b/src/version.c
index 76873d7..59a2bb4 100644
--- a/src/version.c
+++ b/src/version.c
@@ -758,6 +758,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2061,
+/**/
     2060,
 /**/
     2059,