Bring the invite checkbox back, only now disabled by default

src/views/users.html

@@ -87,6 +87,12 @@
             </div>
           </div>
 
+          <div class="checkbox">
+            <label>
+              <input type="checkbox" ng-model="useradd.sendInvite" id="inputUserAddSendInvite"> {{ 'users.addUserDialog.sendInviteCheckbox' | tr }}
+            </label>
+          </div>
+
           <input class="ng-hide" type="submit" ng-disabled="useradd_form.$invalid || useradd.busy"/>
         </form>
       </div>