Update fourslash test

Author: jablko

tests/cases/fourslash/getJavaScriptQuickInfo6.ts

@@ -5,4 +5,4 @@
 /////** @type {function(this:number)} */
 ////function f() { /**/this }
 
-verify.quickInfoAt("", "number");
+verify.quickInfoAt("", "this: number");