fix security bug in login (only allow plaintext password 'password')

functions.php

@@ -685,7 +685,8 @@
 		$pwd_hash = 'SHA1:' . sha1($password);
 
 		$result = db_query($link, "SELECT id,login,access_level FROM ttrss_users WHERE 
-			login = '$login' AND (pwd_hash = '$password' OR pwd_hash = '$pwd_hash')");
+			login = '$login' AND ((pwd_hash = '$password' AND '$password' = 'password')
+				OR pwd_hash = '$pwd_hash')");
 
 		if (db_num_rows($result) == 1) {
 			$_SESSION["uid"] = db_fetch_result($result, 0, "id");