[#4014] Fixed change log typo

modified:   ChangeLog

Author: tmarkwalder

ChangeLog

@@ -11,7 +11,7 @@ Kea 3.1.0 (development) released on July 30, 2025
 
 2379.	[bug]		tmark
 	kea-dhcp4 now correctly supports option class-tags
-	(i.e."client-classes") in host and config backends
+	(i.e."client-classes") in host and config back ends
 	for both MySQL and PosgreSQL.
 	(Gitlab #3770)