Remove unreachable code (per Coveralls)
Remove unreachable code (per Coveralls)

This condition was never reached. Apart from code coverage, it's clear that an exception would not be thrown before this point since only libmongoc functions are called.

jmikola/mongo-php-driver-prototype,mongodb/mongo-php-driver,jmikola/mongo-php-driver-prototype,mongodb/mongo-php-driver,jmikola/mongo-php-driver-prototype,mongodb/mongo-php-driver,jmikola/mongo-php-driver,mongodb/mongo-php-driver,jmikola/mongo-php-driver,mongodb-labs/mongo-php-driver-prototype,jmikola/mongo-php-driver,mongodb-labs/mongo-php-driver-prototype,jmikola/mongo-php-driver,jmikola/mongo-php-driver-prototype,mongodb-labs/mongo-php-driver-prototype,jmikola/mongo-php-driver,jmikola/mongo-php-driver-prototype,mongodb-labs/mongo-php-driver-prototype,mongodb-labs/mongo-php-driver-prototype,mongodb/mongo-php-driver