Revert "Add libdconf-dev to to install-build-deps.sh"

Script is failing on goobuntu-trusty_desktop-stable-amd64 due to packages conflict:
The following packages have unmet dependencies:
 libdconf-dev : Conflicts: libdconf-dev:i386 but 0.20.0-1 is to be installed
 libdconf-dev:i386 : Depends: libglib2.0-dev:i386 (>= 2.25.7) but it is not going to be installed
                     Recommends: libdconf-doc:i386 but it is not installable
                     Conflicts: libdconf-dev but 0.20.0-1 is to be installed

This reverts commit 5b267c0c.

Reason for revert: <INSERT REASONING HERE>

Original change's description:
> Add libdconf-dev to to install-build-deps.sh
> 
> This is the first step in moving from using gconf to dconf.
> 
> Bug: 768027
> Change-Id: Ifb05a6679c38e115b322e0a7caa6c3aad309389e
> Reviewed-on: https://chromium-review.googlesource.com/691097
> Commit-Queue: Tim Brown <timbrown@chromium.org>
> Reviewed-by: Dirk Pranke <dpranke@chromium.org>
> Reviewed-by: Thomas Anderson <thomasanderson@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#505183}

TBR=dpranke@chromium.org,thomasanderson@chromium.org,timbrown@chromium.org

Change-Id: Icec37c78711a2016667ee7f134d5db49b918b7d2
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 768027
Reviewed-on: https://chromium-review.googlesource.com/692974
Commit-Queue: Dirk Pranke <dpranke@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#505391}

build/install-build-deps.sh

@@ -165,7 +165,6 @@ dev_list="\
   libcap-dev
   libcups2-dev
   libcurl4-gnutls-dev
-  libdconf-dev
   libdrm-dev
   libelf-dev
   libffi-dev
@@ -233,7 +232,6 @@ lib_list="\
   libcairo2
   libcap2
   libcups2
-  libdconf1
   libexpat1
   libffi6
   libfontconfig1
@@ -379,7 +377,6 @@ nacl_list="\
   libasound2:i386
   libcap2:i386
   libelf-dev:i386
-  libdconf-dev:i386
   libfontconfig1:i386
   libgconf-2-4:i386
   libglib2.0-0:i386