fix changelog

Author: affeldt-aist

CHANGELOG_UNRELEASED.md

@@ -204,7 +204,8 @@
 - moved from `measurable_structure.v` to `classical_sets.v`:
   + definitions `setI_closed`, `setU_closed`
 
-- moved from `theories` to `theories/topology_theory`
+- moved from `theories` to `theories/topology_theory`:
+  + file `function_spaces.v`
 
 ### Renamed