[MemcachedCache] loadData now returns null instead of false

[em92]

FileCache and SQLiteCache returns null on cache miss. This is important if using strict comparing (for example when using "===")

In #1562 (comment) @markwaters reported, that recent twitter rewrite didn't work when using Memcached.

Probably it happened due to strict comparing here and incorrect return value of loadData (false, instead of null):

rss-bridge/bridges/TwitterBridge.php

Lines 321 to 323 in 06891ae

	$data = $cache->loadData();
	if($data === null) {

Also, @markwaters, please report if this fix works for you.

[markwaters]

Thanks @em92 , I have made the change to MemcachedCache.php and will report back later.

[markwaters]

Thanks @em92 , I have made the change to MemcachedCache.php and will report back later.

Seems like it is working , Thanks again.