Add some missing sigalgs

The SHA1 sigalgs were inadvertently missed off in the sigalgs refactor.
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2157)

ssl/t1_lib.c

@@ -735,6 +735,10 @@ static const unsigned int tls12_sigalgs[] = {
     TLSEXT_SIGALG_rsa_pkcs1_sha384,
     TLSEXT_SIGALG_rsa_pkcs1_sha512,
 
+    TLSEXT_SIGALG_ecdsa_sha1,
+    TLSEXT_SIGALG_rsa_pkcs1_sha1,
+    TLSEXT_SIGALG_dsa_sha1,
+
     TLSEXT_SIGALG_dsa_sha256,
     TLSEXT_SIGALG_dsa_sha384,
     TLSEXT_SIGALG_dsa_sha512