Fix TS error for projects using TS5 (#381)

Author: SanderMuller

src/util/event-formatter.ts

@@ -2,16 +2,11 @@
  * Event name formatter
  */
 export class EventFormatter {
-    /**
-     * Event namespace.
-     */
-    namespace: string | boolean;
-
     /**
      * Create a new class instance.
      */
-    constructor(namespace: string | boolean) {
-        this.setNamespace(namespace);
+    constructor(private namespace: string | boolean) {
+        //
     }
 
     /**