Fixed: Ignore /etc in System disk overview

Co-Authored-By: taloth <taloth@users.noreply.github.com>

src/NzbDrone.Core.Test/DiskSpace/DiskSpaceServiceFixture.cs

@@ -106,6 +106,7 @@ namespace NzbDrone.Core.Test.DiskSpace
         [TestCase("/var/lib/kubelet")]
         [TestCase("/var/lib/docker")]
         [TestCase("/some/place/docker/aufs")]
+        [TestCase("/etc/network")]
         public void should_not_check_diskspace_for_irrelevant_mounts(string path)
         {
             var mount = new Mock<IMount>();

src/NzbDrone.Core/DiskSpace/DiskSpaceService.cs

@@ -20,7 +20,7 @@ namespace NzbDrone.Core.DiskSpace
         private readonly IDiskProvider _diskProvider;
         private readonly Logger _logger;
 
-        private static readonly Regex _regexSpecialDrive = new Regex("^/var/lib/(docker|rancher|kubelet)(/|$)|^/boot(/|$)|/docker(/var)?/aufs(/|$)", RegexOptions.Compiled);
+        private static readonly Regex _regexSpecialDrive = new Regex("^/var/lib/(docker|rancher|kubelet)(/|$)|^/(boot|etc)(/|$)|/docker(/var)?/aufs(/|$)", RegexOptions.Compiled);
 
         public DiskSpaceService(IArtistService artistService, IDiskProvider diskProvider, Logger logger)
         {