allow to set a default expiration for newly created users

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>

templates/webadmin/admin.html

@@ -182,6 +182,16 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
                             </select>
                         </div>
                     </div>
+                    <div class="form-group row">
+                        <label for="idDefaultUsersExpiration" class="col-sm-2 col-form-label">Default users expiration</label>
+                        <div class="col-sm-10">
+                            <input type="number" class="form-control" id="idDefaultUsersExpiration" name="default_users_expiration"
+                                value="{{.Admin.Filters.Preferences.DefaultUsersExpiration}}" min="0" aria-describedby="defaultUsersExpirationHelpBlock">
+                            <small id="defaultUsersExpirationHelpBlock" class="form-text text-muted">
+                                Default expiration for newly created users as number of days
+                            </small>
+                        </div>
+                    </div>
                 </div>
             </div>
 

templates/webadmin/user.html

@@ -1057,6 +1057,10 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
                 showClear: false,
                 showClose: true,
                 showToday: false
+            },
+            widgetPositioning: {
+                horizontal: 'auto',
+                vertical: 'bottom'
             }
         });