Git::unquote_path(): handle '\a'

unquote_path() does not handle quoted paths containing '\a',
even though quote.c::unquote_c_style() does, and quote.c:sq_lookup[]
tells quote.c::sq_must_quote() that '\007' must be quoted as '\a'.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

perl/Git.pm

@@ -1461,6 +1461,7 @@ when not using -z or when parsing the output of diff -u.
 
 {
 	my %cquote_map = (
+		"a" => chr(7),
 		"b" => chr(8),
 		"t" => chr(9),
 		"n" => chr(10),
@@ -1487,7 +1488,7 @@ when not using -z or when parsing the output of diff -u.
 					$_ = $2;
 					last;
 				}
-				if (/^([\\\042btnvfr])(.*)$/) {
+				if (/^([\\\042abtnvfr])(.*)$/) {
 					$retval .= $cquote_map{$1};
 					$_ = $2;
 					last;