Use "/usr/bin/env bash" for build-wrapper.sh

PR #426 <https://github.com/Genymobile/scrcpy/pull/426>
Signed-off-by: NRomain Vimont <rom@rom1v.com>

server/scripts/build-wrapper.sh

-#!/bin/bash
+#!/usr/bin/env bash
 # Wrapper script to invoke gradle from meson
 set -e