fix link

Author: Alain Dumesny

doc/CHANGES.md

@@ -28,7 +28,7 @@ Change log
 ## v0.5.5-dev (upcoming changes)
 
 - add `float(val)` to set/get the grid float mode [#1088](https://github.com/gridstack/gridstack.js/pull/1088)
-- Allow percentage as a valid unit for height [#1089](https://github.com/gridstack/gridstack.js/pull/1089)
+- Allow percentage as a valid unit for height [#1093](https://github.com/gridstack/gridstack.js/pull/1093)
 
 ## v0.5.5 (2019-11-27)