use Option.iter for eTag and lastModified values at Precondition.fs, due to ionide-analyzers HandleOptionGracefullyAnalyzer

Author: 64J0

src/Giraffe/Preconditional.fs

@@ -153,9 +153,11 @@ type PreconditionExtensions() =
             | ConditionFailed       -> ConditionFailed
             | ResourceNotModified   -> ResourceNotModified
 
-        // Set ETag and Last-Modified in the response
-        if eTag.IsSome         then responseHeaders.ETag         <- eTag.Value
-        if lastModified.IsSome then responseHeaders.LastModified <- Nullable(lastModified.Value.CutOffMs())
+        // Set ETag in the response
+        eTag |> Option.iter (fun eTagValue -> responseHeaders.ETag <- eTagValue)
+
+        // Set Last-Modified in the response
+        lastModified |> Option.iter (fun lastModifiedValue -> responseHeaders.LastModified <- Nullable(lastModifiedValue.CutOffMs()))
 
         // Validate headers in correct precedence
         // RFC: https://tools.ietf.org/html/rfc7232#section-6