Remove system.net.http unused reference

Xamarin.PropertyEditing.Windows.Standalone/Xamarin.PropertyEditing.Windows.Standalone.csproj

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="14.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
   <PropertyGroup>
@@ -57,7 +57,6 @@
     <Reference Include="System.Core" />
     <Reference Include="System.Xml.Linq" />
     <Reference Include="System.Data.DataSetExtensions" />
-    <Reference Include="System.Net.Http" />
     <Reference Include="System.Xaml">
       <RequiredTargetFramework>4.0</RequiredTargetFramework>
     </Reference>

Xamarin.PropertyEditing.Windows/Xamarin.PropertyEditing.Windows.csproj

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" ToolsVersion="14.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
   <PropertyGroup>
@@ -43,7 +43,6 @@
     <Reference Include="System.Data.DataSetExtensions" />
     <Reference Include="Microsoft.CSharp" />
     <Reference Include="System.Data" />
-    <Reference Include="System.Net.Http" />
     <Reference Include="System.Xml" />
     <Reference Include="UIAutomationProvider" />
     <Reference Include="WindowsBase" />