PHPC-609: Free mongoc_uri_t if RC/RP/WC application fails
PHPC-609: Free mongoc_uri_t if RC/RP/WC application fails

This resolves a memory leak introduced in 12ec628855d06aa08c9c4dfa8bdb37cbcee002c6.

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