mp3cut makes output file executable

[Jani Uusitalo]

== Steps to reproduce ==
$ wget -q 'https://upload.wikimedia.org/wikipedia/commons/a/a5/Uncle_Josh_and_the_Insurance_Company_-_Cal_Stewart.mp3' && mp3cut -o test.mp3 Uncle_Josh_and_the_Insurance_Company_-_Cal_Stewart.mp3 &>/dev/null && ls -l test.mp3

== Expected result ==
-rw-r--r-- 1 jani jani 2433848 maali 26 15:45 test.mp3

== Actual result ==
-rwxr--r-- 1 jani jani 2433848 maali 26 15:45 test.mp3

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: poc-streamer 0.4.2-4build1
ProcVersionSignature: Ubuntu 4.15.0-12.13-generic 4.15.7
Uname: Linux 4.15.0-12-generic x86_64
ApportVersion: 2.20.8-0ubuntu10
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Mon Mar 26 15:49:22 2018
Dependencies:
 gcc-8-base 8-20180321-1ubuntu1
 libc6 2.27-0ubuntu2
 libgcc1 1:8-20180321-1ubuntu1
InstallationDate: Installed on 2016-10-13 (528 days ago)
InstallationMedia: Ubuntu-Server 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=fi_FI.UTF-8
 SHELL=/bin/bash
SourcePackage: poc-streamer
UpgradeStatus: No upgrade log present (probably fresh install)