Fix typo in CHANGELOG version entry (#71)

CHANGELOG.md

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b12b8e9..397be1d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,4 @@
-## 2.10.0-nullsafety.1
+## 1.10.0-nullsafety.1
 
 - Allow 2.10 stable and 2.11.0 dev SDK versions.