Fixed problem with opening non-existing files through CachingFileStorage

src/Kp2aBusinessLogic/Io/BuiltInFileStorage.cs

@@ -66,7 +66,7 @@ namespace keepass2android.Io
 			{
 				if ((ex.Response is HttpWebResponse) && (((HttpWebResponse)ex.Response).StatusCode == HttpStatusCode.NotFound))
 				{
-					throw new FileNotFoundException("404!", ioc.Path, ex);
+					throw new FileNotFoundException(ex.Message, ioc.Path, ex);
 				}
 				throw;
 			}

src/Kp2aBusinessLogic/Io/CachingFileStorage.cs

@@ -146,6 +146,9 @@ namespace keepass2android.Io
 			}
 			catch (Exception ex)
 			{
+				if (!IsCached(ioc))
+					throw;
+
 				Kp2aLog.Log("couldn't open from remote " + ioc.Path);
 				Kp2aLog.Log(ex.ToString());