remove merged repeat code

Author: sarvesh-s

src/ResourceManager/Sql/Commands.Sql/Database Backup/Services/AzureSqlDatabaseBackupCommunicator.cs

@@ -48,11 +48,6 @@ public class AzureSqlDatabaseBackupCommunicator
         /// </summary>
         private static ResourceManagementClient ResourcesClient { get; set; }
 
-        /// <summary>
-        /// The Sql client to be used by this end points communicator
-        /// </summary>
-        private static Management.Sql.SqlManagementClient SqlArmClient { get; set; }
-
         /// <summary>
         /// Gets or set the Azure subscription
         /// </summary>