Fujitsu-Siemens U9210: Headphone output stuck on low volume (fix included)

On a stock installation, the headphone volume is stuck low and cannot be adjusted.

It turns out that PulseAudio mutes the output "Speaker+LO" when headphones are inserted, which is against what we want.

The problem can be fixed by modifying the section "Element Speaker+LO" in /usr/share/pulseaudio/alsa-mixer/paths/analog-output-headphones.conf as follows:

Before:

[Element Speaker+LO]
switch = off
volume = off

After:

[Element Speaker+LO]
switch = on
volume = merge

However, I suppose committing this change as-is might break some other machines. Is there a way to make a machine-specific exception for this laptop?

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: pulseaudio 1:8.0-0ubuntu3.2 [modified: usr/share/pulseaudio/alsa-mixer/paths/analog-output-headphones.conf]
ProcVersionSignature: Ubuntu 4.4.0-77.98-generic 4.4.59
Uname: Linux 4.4.0-77-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.5
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: joonas 1638 F.... pulseaudio
CurrentDesktop: Unity
Date: Tue May 16 11:47:40 2017
InstallationDate: Installed on 2016-11-14 (182 days ago)
InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
SourcePackage: pulseaudio
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 12/11/2009
dmi.bios.vendor: Phoenix
dmi.bios.version: S118D0FR.112 - R081 - 1659
dmi.board.asset.tag: Tag 12345
dmi.board.name: S118DB
dmi.board.vendor: FUJITSU SIEMENS
dmi.board.version: 12
dmi.chassis.type: 10
dmi.chassis.vendor: FUJITSU SIEMENS
dmi.chassis.version: 1.2
dmi.modalias: dmi:bvnPhoenix:bvrS118D0FR.112-R081-1659:bd12/11/2009:svnFUJITSUSIEMENS:pnESPRIMOMobileU9210:pvr1.0:rvnFUJITSUSIEMENS:rnS118DB:rvr12:cvnFUJITSUSIEMENS:ct10:cvr1.2:
dmi.product.name: ESPRIMO Mobile U9210
dmi.product.version: 1.0
dmi.sys.vendor: FUJITSU SIEMENS