[!!!][BUGFIX] Respect PageTsConfig limitation for authors

From now on the PAGE_TSCONFIG_ID is respected for authors in the backend.

If you have not configured a storage pid for this records before please adjust your configuration.

TsConfig Example:
TCEFORM.pages.authors.PAGE_TSCONFIG_ID = 59

Fixes: #123

Configuration/TCA/Overrides/pages.php

@@ -190,6 +190,7 @@
                 'renderType' => 'selectMultipleSideBySide',
                 'multiple' => 0,
                 'foreign_table' => 'tx_blog_domain_model_author',
+                'foreign_table_where' => 'AND tx_blog_domain_model_author.pid = ###PAGE_TSCONFIG_ID### ORDER BY tx_blog_domain_model_author.name ASC',
                 'MM' => 'tx_blog_post_author_mm',
                 'minitems' => 0,
                 'maxitems' => 99999,