Updated record for 'u' in Extensions Registry

[Doug Ewell]

I wrote:
 
> This is a last call to see whether the maintaining authority for BCP
> 47 has any plans to correct the entry for extension 'u' in the
> Language Tag Extensions Registry that contains an overlong line.

Should have been:

"... to see whether the maintaining authority for BCP 47 extension 'u'
has any plans to correct the entry..."

--
Doug Ewell | Thornton, CO, USA
http://ewellic.org | @DougEwell