Remove 'gss-sha1-krb5' from KEX default.

Simon tells me it was left over from an abandoned configuration design
for GSS key exchange. Let's get rid of it before it starts cluttering
snapshot users' saved sessions.

settings.c

@@ -917,10 +917,10 @@ void load_open_settings(void *sesskey, Conf *conf)
 	 * a server which offered it then choked, but we never got
 	 * a server version string or any other reports. */
 	const char *default_kexes,
-                   *normal_default = "gss-sha1-krb5,ecdh,dh-gex-sha1,"
+		   *normal_default = "ecdh,dh-gex-sha1,dh-group14-sha1,rsa,"
-                       "dh-group14-sha1,rsa,WARN,dh-group1-sha1",
+		       "WARN,dh-group1-sha1",
-                   *bugdhgex2_default = "gss-sha1-krb5,ecdh,dh-group14-sha1,"
+		   *bugdhgex2_default = "ecdh,dh-group14-sha1,rsa,"
-                       "rsa,WARN,dh-group1-sha1,dh-gex-sha1";
+		       "WARN,dh-group1-sha1,dh-gex-sha1";
 	char *raw;
 	i = 2 - gppi_raw(sesskey, "BugDHGEx2", 0);
 	if (i == FORCE_ON)
@@ -947,6 +947,13 @@ void load_open_settings(void *sesskey, Conf *conf)
 	    sfree(raw);
 	    raw = dupstr(normal_default);
 	}
+	/* (For the record: after 0.70, the default algorithm list
+	 * very briefly contained the string 'gss-sha1-krb5'; this was
+	 * never used in any committed version of code, but was left
+	 * over from a pre-commit version of GSS key exchange.
+	 * Mentioned here as it is remotely possible that it will turn
+	 * up in someone's saved settings in future.) */
+	
         gprefs_from_str(raw, kexnames, KEX_MAX_CONF, conf, CONF_ssh_kexlist);
 	sfree(raw);
     }