Use /usr/bin/env shebang for bash userscripts

See #1665

misc/userscripts/dmenu_qutebrowser

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Copyright 2015 Zach-Button <zachrey.button@gmail.com>
 #

misc/userscripts/open_download

@@ -1,4 +1,4 @@
-#!/bin/bash -e
+#!/usr/bin/env bash -e
 # Both standalone script and qutebrowser userscript that opens a rofi menu with
 # all files from the download director and opens the selected file. It works
 # both as a userscript and a standalone script that is called from outside of

misc/userscripts/password_fill

@@ -1,4 +1,4 @@
-#!/bin/bash -e
+#!/usr/bin/env bash -e
 help() {
     blink=$'\e[1;31m' reset=$'\e[0m'
 cat <<EOF

misc/userscripts/qutebrowser_viewsource

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Copyright 2015 Zach-Button <zachrey.button@gmail.com>
 #

misc/userscripts/taskadd

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Behavior:
 #   Userscript for qutebrowser which adds a task to taskwarrior.

misc/userscripts/view_in_mpv

@@ -1,4 +1,4 @@
-#!/bin/bash -e
+#!/usr/bin/env bash -e
 #
 # Behavior:
 #   Userscript for qutebrowser which views the current web page in mpv using