Remove the period after the git-check-attr summary

The period at the end of the git-check-attr summary causes there to be
two periods after the summary in the git(1) manual page.

Signed-off-by: Matt Kraai <kraai@ftbfs.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-check-attr.txt

@@ -3,7 +3,7 @@ git-check-attr(1)
 
 NAME
 ----
-git-check-attr - Display gitattributes information.
+git-check-attr - Display gitattributes information
 
 
 SYNOPSIS