Read any non-empty input when prompting for an input like 2fa code or auth code

DepotDownloader/ContentDownloader.cs

@@ -243,7 +243,7 @@ namespace DepotDownloader
                 if (node_encrypted != KeyValue.Invalid)
                 {
                     var password = Config.BetaPassword;
-                    if (password == null)
+                    while (string.IsNullOrEmpty(password))
                     {
                         Console.Write("Please enter the password for branch {0}: ", branch);
                         Config.BetaPassword = password = Console.ReadLine();

DepotDownloader/Program.cs

@@ -284,7 +284,7 @@ namespace DepotDownloader
                     }
 
                     Console.WriteLine();
-                } while (String.Empty == password);
+                } while (string.Empty == password);
             }
             else if (username == null)
             {

DepotDownloader/Steam3Session.cs

@@ -597,9 +597,12 @@ namespace DepotDownloader
                 }
 
                 if (is2FA)
+                {
+                    do
                     {
                         Console.Write("Please enter your 2 factor auth code from your authenticator app: ");
                         logonDetails.TwoFactorCode = Console.ReadLine();
+                    } while (String.Empty == logonDetails.TwoFactorCode);
                 }
                 else if (isLoginKey)
                 {
@@ -620,9 +623,12 @@ namespace DepotDownloader
                     }
                 }
                 else
+                {
+                    do
                     {
                         Console.Write("Please enter the authentication code sent to your email address: ");
                         logonDetails.AuthCode = Console.ReadLine();
+                    } while (string.Empty == logonDetails.AuthCode);
                 }
 
                 Console.Write("Retrying Steam3 connection...");