Drop yearly range from copyright notice

This has been done across the code base years ago[1], so we follow
suit.  While we're at it, we also remove the obsolete information about
PHP 7 compatibility.

[1] <http://github.com/php/php-src/commit/0cf7de1c70a459a1207aea9efa780777faa96f2e>

Author: cmb69

sapi/isapi/php7isapi.c

@@ -1,8 +1,6 @@
 /*
    +----------------------------------------------------------------------+
-   | PHP Version 7                                                        |
-   +----------------------------------------------------------------------+
-   | Copyright (c) 1997-2015 The PHP Group                                |
+   | Copyright (c) The PHP Group                                          |
    +----------------------------------------------------------------------+
    | This source file is subject to version 3.01 of the PHP license,      |
    | that is bundled with this package in the file LICENSE, and is        |