[hotfix] Fix bug that made impossible to send an email

src/app/core/components/contact/contact.component.html

@@ -179,7 +179,7 @@
 
         <div class="has-text-right button-wrapper">
           <button class="button button-gl is-outlined" type="button" [disabled]="formDisabled" (click)="cancel()" i18n="@@contact.cancel">Cancel</button>
-          <button type="submit" class="button button-gl" [ngClass]="{'is-loading': formDisabled}" [disabled]="formIsInvalid() || formDisabled"
+          <button type="submit" class="button button-gl" [ngClass]="{'is-loading': formDisabled}" [disabled]="formIsInvalid || formDisabled"
             i18n="@@contact.send">Send</button>
         </div>
       </div>

src/app/core/components/contact/contact.component.ts

@@ -97,7 +97,7 @@ export class ContactComponent implements OnInit {
 
   // Return true if one of the fields at least doesn't respect its validators
   // or if the confirmation email is different from the email
-  formIsInvalid() {
+  get formIsInvalid() {
     const controls = this.form.controls;
     const value = this.form.invalid || this.emailConfirmationError;
     return value;