detect language not required when explicitly sending language

Author: russcam

src/Nest/Mapping/Types/Specialized/Attachment/Attachment.cs

@@ -44,8 +44,7 @@ public class Attachment
 		public string Keywords { get; set; }
 
 		/// <summary>
-		/// The language of the attachment. Can be explicitly set. This requires
-		/// <see cref="DetectLanguage"/> to be set to <c>true</c>
+		/// The language of the attachment. Can be explicitly set.
 		/// </summary>
 		[JsonProperty("language")]
 		public string Language { get; set; }

src/Tests/Document/Single/Attachment/AttachmentApiTests.cs

@@ -201,10 +201,7 @@ public class AttachmentExplicitWithMetadataApiTests : AttachmentApiTestsBase
 					ContentType = "application/pdf",
 					Content = Content,
 					Name = "content name",
-					// in order to explicitly send language metadata,
-					// detect_language also needs to be set to true
-					Language = "en",
-					DetectLanguage = true
+					Language = "en"
 				}
 			};
 
@@ -220,8 +217,7 @@ public AttachmentExplicitWithMetadataApiTests(IndexingCluster cluster, EndpointU
 					_content = Content,
 					_content_type = "application/pdf",
 					_name = "content name",
-					_language = "en",
-					_detect_language = true
+					_language = "en"
 				}
 			};