Make SSL_{CTX}_set_tmp_ecdh() call SSL_{CTX_}set1_curves()

SSL_{CTX}_set_tmp_ecdh() allows to set 1 EC curve and then tries to use it.  On
the other hand SSL_{CTX_}set1_curves() allows you to set a list of curves, but
only when SSL_{CTX_}set_ecdh_auto() was called to turn it on.

Reviewed-by: Dr. Stephen Henson <steve@openssl.org>

ssl/ssl_lib.c

@@ -2037,7 +2037,7 @@ void ssl_set_masks(SSL *s, const SSL_CIPHER *cipher)
 #endif
 
 #ifndef OPENSSL_NO_EC
-    have_ecdh_tmp = (c->ecdh_tmp || c->ecdh_tmp_auto);
+    have_ecdh_tmp = c->ecdh_tmp_auto;
 #endif
     cpk = &(c->pkeys[SSL_PKEY_RSA_ENC]);
     rsa_enc = pvalid[SSL_PKEY_RSA_ENC] & CERT_PKEY_VALID;