ifnet: properly unquote hostnames with g_shell_unquote() (bgo #669148)

If /etc/conf.d/hostname contains "hostname='foo'", then the hostname
needs to be set to "foo", not "'foo'".

https://bugzilla.gnome.org/show_bug.cgi?id=669148

src/settings/plugins/ifnet/net_utils.c

@@ -242,8 +242,7 @@ read_hostname (const char *path)
 		if (g_str_has_prefix (all_lines[i], "hostname")) {
 			tmp = strstr (all_lines[i], "=");
 			tmp++;
-			tmp = strip_string (tmp, '"');
-			result = g_strdup (tmp);
+			result = g_shell_unquote (tmp, NULL);
 			break;
 		}