Update button to not submit the form

src/app/login/login.component.html

@@ -14,5 +14,5 @@
     <mat-error *ngIf="passwordFormControl.hasError('required')">Password is <strong>required</strong>.</mat-error>
   </mat-form-field>
   <button mat-raised-button color="primary" type="submit">Login</button>
-  <button mat-raised-button *ngIf="role === UserRole.PARTICIPANT" (click)="guestLogin()">Login as guest</button>
+  <button mat-raised-button *ngIf="role === UserRole.PARTICIPANT" (click)="guestLogin()" type="button">Login as guest</button>
 </form>