Add missing localization used in TokenAuthController

Author: acjh

aspnet-core/src/AbpCompanyName.AbpProjectName.Core/Localization/SourceFiles/AbpProjectName.xml

@@ -78,6 +78,7 @@
 
     <text name="CouldNotCompleteLoginOperation">Could not complete login operation. Please try again later.</text>
 
+    <text name="CouldNotValidateExternalUser">Could not validate external user</text>
     <text name="EditRole">Edit role</text>
     <text name="EditTenant">Edit tenant</text>
     <text name="EditUser">Edit user</text>