New: Set KeepAlive for metadata requests

src/NzbDrone.Common/Cloud/LidarrCloudRequestBuilder.cs

@@ -17,6 +17,7 @@ namespace NzbDrone.Common.Cloud
                 .CreateFactory();
 
             Search = new HttpRequestBuilder("https://api.lidarr.audio/api/v0.4/{route}")
+                .KeepAlive()
                 .CreateFactory();
         }
 

src/NzbDrone.Core/MetadataSource/IMetadataRequestBuilder.cs

@@ -26,7 +26,7 @@ namespace NzbDrone.Core.MetadataSource
         {
             if (_configService.MetadataSource.IsNotNullOrWhiteSpace())
             {
-                return new HttpRequestBuilder(_configService.MetadataSource.TrimEnd("/") + "/{route}").CreateFactory();
+                return new HttpRequestBuilder(_configService.MetadataSource.TrimEnd("/") + "/{route}").KeepAlive().CreateFactory();
             }
             else
             {