Bump System.Net.Http from 4.3.3 to 4.3.4 in /XamarinFileUploader.iOS

Bumps System.Net.Http from 4.3.3 to 4.3.4.

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

XamarinFileUploader.iOS/packages.config

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
   <package id="Newtonsoft.Json" version="9.0.1" targetFramework="xamarinios10" />
-  <package id="System.Net.Http" version="4.3.3" targetFramework="xamarinios10" />
+  <package id="System.Net.Http" version="4.3.4" targetFramework="xamarinios10" />
   <package id="Xamarin.Forms" version="3.4.0.1009999" targetFramework="xamarinios10" />
 </packages>