PHPLIB-229: Declare read concern wire version for Find operation
PHPLIB-229: Declare read concern wire version for Find operation

This property was missing from 8dcc778422a5370196fc8436ef80958d724ca9da.

10gen-labs/mongo-php-library-prototype,mongodb/mongo-php-library,derickr/mongo-php-library,jmikola/mongo-php-library,jmikola/mongo-php-library,mongodb/mongo-php-library,mongodb/mongo-php-library,mongodb/mongo-php-library,jmikola/mongo-php-library-prototype,jmikola/mongo-php-library,jmikola/mongo-php-library,derickr/mongo-php-library-prototype,mongodb-labs/mongo-php-library-prototype,derickr/mongo-php-library