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 <user1@example.com>

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

Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/perl/Git/SVN.pm b/perl/Git/SVN.pm
index 76b2965..4b28b87 100644
--- a/perl/Git/SVN.pm
+++ b/perl/Git/SVN.pm
@@ -1491,6 +1491,10 @@
 
 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)';
 	}