FIX Capitalisation fixes in welcome back message (#9439)

docs/en/02_Developer_Guides/01_Templates/02_Common_Variables.md

@@ -54,7 +54,7 @@ Returns the currently logged in [Member](api:SilverStripe\Security\Member) insta
 
 ```ss
 <% if $CurrentMember %>
-  Welcome Back, $CurrentMember.FirstName
+  Welcome back, $CurrentMember.FirstName
 <% end_if %>
 ```
 

docs/en/02_Developer_Guides/06_Testing/How_Tos/01_Write_a_FunctionalTest.md

@@ -44,7 +44,7 @@ class HomePageTest extends FunctionalTest
         $page = $this->get('home/');
 
         $this->assertExactHTMLMatchBySelector("#Welcome", [
-            'Welcome Back'
+            'Welcome back'
         ]);
     }
 }

lang/en.yml

@@ -276,7 +276,7 @@ en:
     SURNAME: Surname
     VALIDATIONADMINLOSTACCESS: 'Cannot remove all admin groups from your profile'
     ValidationIdentifierFailed: 'Can''t overwrite existing member #{id} with identical identifier ({name} = {value}))'
-    WELCOMEBACK: 'Welcome Back, {firstname}'
+    WELCOMEBACK: 'Welcome back, {firstname}'
     YOUROLDPASSWORD: 'Your old password'
     belongs_many_many_Groups: Groups
     db_Locale: 'Interface Locale'

src/Security/MemberAuthenticator/LoginHandler.php

@@ -201,7 +201,7 @@ class LoginHandler extends RequestHandler
             // Welcome message
             $message = _t(
                 'SilverStripe\\Security\\Member.WELCOMEBACK',
-                'Welcome Back, {firstname}',
+                'Welcome back, {firstname}',
                 ['firstname' => $member->FirstName]
             );
             Security::singleton()->setSessionMessage($message, ValidationResult::TYPE_GOOD);