lint(combobox): removed trailing whitespace.

Author: nielsr98

src/cdk-experimental/combobox/combobox.spec.ts

@@ -379,6 +379,7 @@ describe('Combobox', () => {
     No Value
   </button>
   <div id="other-content"></div>
+
   <ng-template cdkComboboxPanel #panel="cdkComboboxPanel">
     <div dialogContent #dialog="dialogContent" [parentPanel]="panel">
       <input #input>