switch to SHA1.Create from new SHA1Managed (needs to be tested)

src/S7CommPlusDriver/S7CommPlusConnection.cs

@@ -582,7 +582,7 @@ public int Connect(string address, string password = "", int timeoutMs = 5000)
 
                 // Calculate challengeResponse [sha1(password) xor challenge]
                 byte[] challengeResponse;
-                using (SHA1Managed sha1 = new SHA1Managed())
+                using (var sha1 = SHA1.Create())
                 {
                     challengeResponse = sha1.ComputeHash(Encoding.UTF8.GetBytes(password));
                 }