patch 8.2.0101: crash when passing null object to ":echomsg"

Problem:    Crash when passing null object to ":echomsg".
Solution:   Check for NULL pointer. (Yasuhiro Matsumoto, closes #5460)
diff --git a/src/version.c b/src/version.c
index 1c68c1a..ba690bc 100644
--- a/src/version.c
+++ b/src/version.c
@@ -743,6 +743,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    101,
+/**/
     100,
 /**/
     99,