Add DHCP static lease modal closed on touch within the modal in mobile browser

### Prerequisites

- [x] I have checked the [Wiki](https://github.com/AdguardTeam/AdGuardHome/wiki) and [Discussions](https://github.com/AdguardTeam/AdGuardHome/discussions/categories/q-a) and found no answer

- [x] I have searched other issues and found no duplicates

- [x] I want to report a bug and not [ask a question or ask for help](https://github.com/AdguardTeam/AdGuardHome/discussions/categories/q-a)

- [x] I have set up AdGuard Home correctly and [configured clients to use it](https://github.com/AdguardTeam/AdGuardHome/wiki/Clients). (Use the [Discussions](https://github.com/AdguardTeam/AdGuardHome/discussions/categories/q-a) for help with installing and configuring clients.)

### Platform (OS and CPU architecture)

Linux, ARM64

### Installation

GitHub releases or script from README

### Setup

On one machine

### AdGuard Home version

v0.107.67

### Action

When filling out the fields inside the "add static lease" modal form using a mobile phone, touching anything inside the modal closes the modal.

This makes it impossible to use a mobile phone to add a new DHCP static lease with AdGuard Home web dashboard.

### Expected result

Don't close the modal when touching any elements inside the modal

### Actual result

Touching any elements inside the modal closes the modal

### Additional information and/or screenshots

Phone: Galaxy S25
Android Version: 18
Browser: Edge 140.0.3485.98