Don't limit message sizes in ssl3_get_cert_verify.

PR#319 (reoponed version).

(Imported from upstream's 8358302d47)

Change-Id: I222c454620ab445d4906ee2c2b6a9ad80e56018e

ssl/s3_srvr.c

@@ -2539,7 +2539,7 @@ int ssl3_get_cert_verify(SSL *s)
 		SSL3_ST_SR_CERT_VRFY_A,
 		SSL3_ST_SR_CERT_VRFY_B,
 		SSL3_MT_CERTIFICATE_VERIFY,
-		516, /* Enough for 4096 bit RSA key with TLS v1.2 */
+		SSL3_RT_MAX_PLAIN_LENGTH,
 		&ok);
 
 	if (!ok) return((int)n);