chore(igx-radio-directive): Fix wrong merge in radio sample (#1610)

Author: Borislav Kulov

src/app/radio/radio.sample.html

@@ -30,7 +30,7 @@ <h4 class="sample-title">Radio group in template-driven form</h4>
                 </div>
                 <div>
                     <label for="radioGroupSeasons">Favorite season </label>
-                    <igx-- id="radioGroupSeasons" name="radioGroupSeasons" labelPosition="before" [(ngModel)]="personBob.favoriteSeason">
+                    <igx-radio-group id="radioGroupSeasons" name="radioGroupSeasons" labelPosition="before" [(ngModel)]="personBob.favoriteSeason">
                         <igx-radio class="radio-sample" *ngFor="let item of seasons" value="{{item}}">
                             {{item}}
                         </igx-radio>