verify-tag: also grok CR/LFs in the tag signature

On some people's favorite platform, gpg outputs signatures
with CR/LF line endings.  So verify-tag has to play nice with
them.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin-verify-tag.c

@@ -35,7 +35,7 @@ static int run_gpg_verify(const char *buf, unsigned long size, int verbose)
 
 	/* find the length without signature */
 	len = 0;
-	while (len < size && prefixcmp(buf + len, PGP_SIGNATURE "\n")) {
+	while (len < size && prefixcmp(buf + len, PGP_SIGNATURE)) {
 		eol = memchr(buf + len, '\n', size - len);
 		len += eol ? eol - (buf + len) + 1 : size - len;
 	}