Merge pull request #3703 from oddstr13/pr-username-space-1

Allow space in username

(cherry picked from commit 8ab800508bb140d8671125245a64c9d27adcad13)
Signed-off-by: Joshua M. Boniface <joshua@boniface.me>

Jellyfin.Server.Implementations/Users/UserManager.cs

@@ -758,8 +758,8 @@ namespace Jellyfin.Server.Implementations.Users
         {
             // This is some regex that matches only on unicode "word" characters, as well as -, _ and @
             // In theory this will cut out most if not all 'control' characters which should help minimize any weirdness
-            // Usernames can contain letters (a-z + whatever else unicode is cool with), numbers (0-9), at-signs (@), dashes (-), underscores (_), apostrophes ('), and periods (.)
-            return Regex.IsMatch(name, @"^[\w\-'._@]*$");
+            // Usernames can contain letters (a-z + whatever else unicode is cool with), numbers (0-9), at-signs (@), dashes (-), underscores (_), apostrophes ('), periods (.) and spaces ( )
+            return Regex.IsMatch(name, @"^[\w\ \-'._@]*$");
         }
 
         private IAuthenticationProvider GetAuthenticationProvider(User user)