git-svn: trim leading and trailing whitespaces in author name

In some cases, the svn author names might contain leading or trailing
whitespaces, leading to messages such as:

  Author: user1
   not defined in authors.txt

(the trailing newline leads to the line break). The user "user1" is
defined in authors.txt though, e.g.

  user1 = User <[email protected]>

Fix this by trimming the author name retreived from svn before using it
in check_author.

Helped-by: Eric Sunshine <[email protected]>
Signed-off-by: Tobias Klauser <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

perl/Git/SVN.pm

@@ -1491,6 +1491,10 @@ sub call_authors_prog {
 
 sub check_author {
 	my ($author) = @_;
+	if (defined $author) {
+		$author =~ s/^\s+//g;
+		$author =~ s/\s+$//g;
+	}
 	if (!defined $author || length $author == 0) {
 		$author = '(no author)';
 	}