Update php-apc pacakge to 3.1.9.

3.1.9 (stable)
- Fix regression introduced in 3.1.8 (#22687)

3.1.8 (stable)
- Windows read-write locks support on Windows XP or later and Windows
  Win7 or later (use php_apc-xp.dll or php_apc-win7.dll)
- Fix variable type check in user cache update
- Make warnings that user cannot do anything about debug messages
- Fixed bug #21400 (Minor memory leak in MINFO)
- Fixed bug #18890: Ensure that --enable-apc-debug=no disables debug mode.
- Fixed bug #19459: check for expiry while looping through the iterator slots

3.1.7 (beta)
- pthread read-write locks support
- apc.serializer hooks, export apc_serializer.h as an API
- Fix regression bug #20529: Look up files in CWD
- Pool allocator fixes for large allocations
- trunk compat fixes (Kalle)
- ZTS fixes (Pierre, Hirokawa)
- Readability and warning fixes (Pierre, Kalle)

(taca)