Make the link in printfooter explicitly ltr

Without this, in RTL wikis the "http" appears
in the middle of the URL.

To test, set
$wgLanguageCode = "he";
create an article called "ספר", view it in print mode
and note the URL at the bottom.

Change-Id: I1c0194c5cbd186e953eb0fc49184caa66c436ad1
Merge "Make the link in printfooter explicitly ltr"