title: Using GetAwaiting with unique class attribute is raising error in MVC 5
body: <p>Dears, I am trying to use a unique index class attribute to prevent application to save save data</p>
  
  <pre><code>public class Ports
  {
      public short PortsID { get; set; }
  
      [Required] [Column(TypeName = "NVARCHAR")][StringLength(10)] [Index(IsUnique = true)]
      [Remote("IsPortExist", "Ports", AdditionalFields = "PortsID",
              ErrorMessage = "Port name already exists")]
      public string Portname { get; set; }
      public string address { get; set; }
      public string Country { get; set; }
      public string City { get; set; }
  
      //[InverseProperty("POL")]
      //public virtual ICollection&lt;RateRequests&gt; Portofloading { get; set; }
  
      //[InverseProperty("POD")]
      //public virtual ICollection&lt;RateRequests&gt; Portofdischarge { get; set; }
  }
  
  public async Task&lt;JsonResult&gt; IsPortExist(string PortName, int? Id)
      {
          bool isPortExist = await db.ports.Any(x =&gt; x.Portname == PortName &amp;&amp; x.PortsID != Id);
  
          return Json(!isPortExist, JsonRequestBehavior.AllowGet);
      }
  </code></pre>
  
  <p>the error is 'bool' doesnot contain a definition for a 'GetAwaiter' and no accessible extension method 'Getawaiter' accepting a first argument of type bool could be found, note i am using frame work 4.6.1</p>
  
  <p>Thanks in advance </p>