#19020: Fixing email validation

Work Item: 19020

--HG--
branch : 1.x

src/Orchard.Tests.Modules/Users/Controllers/AccountControllerTests.cs

@@ -170,6 +170,7 @@ namespace Orchard.Tests.Modules.Users.Controllers {
                 @"wo..oly@example.com",
                 @"pootietang.@example.com",
                 @".@example.com",
+                @"@example.com",
                 @"Ima Fool@example.com")]
             string email) {
 

src/Orchard.Web/Modules/Orchard.Users/Models/UserPart.cs

@@ -3,7 +3,9 @@ using Orchard.Security;
 
 namespace Orchard.Users.Models {
     public sealed class UserPart : ContentPart<UserPartRecord>, IUser {
-        public const string EmailPattern = @"^(?!\.)(""([^""\r\\]|\\[""\r\\])*""|([-a-z0-9!#$%&'*+/=?^_`{|}~]|(?<!\.)\.)*)(?<!\.)@[a-z0-9][\w\.-]*[a-z0-9]\.[a-z][a-z\.]*[a-z]$";
+        public const string EmailPattern = 
+            @"^(?![\.@])(""([^""\r\\]|\\[""\r\\])*""|([-a-z0-9!#$%&'*+/=?^_`{|}~]|(?<!\.)\.)*)(?<!\.)"
+            + @"@[a-z0-9][\w\.-]*[a-z0-9]\.[a-z][a-z\.]*[a-z]$";
 
         public string UserName {
             get { return Record.UserName; }