[openlayers] Update definition version (#11819)

The definition file is for v3.18.2. During the merge from master, the version has not been updated and remained 3.6.0.

openlayers/index.d.ts

@@ -1,4 +1,4 @@
-// Type definitions for OpenLayers v3.6.0
+// Type definitions for OpenLayers v3.18.2
 // Project: http://openlayers.org/
 // Definitions by: Olivier Sechet <https://github.com/osechet>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
@@ -13786,4 +13786,4 @@ declare module olx {
 
 declare module "openlayers" {
     export = ol;
-}
+}