Remove suggest mongo-php-adapter
Remove suggest mongo-php-adapter

It is already suggested by doctrine/mongodb which is required by this
library.

doctrine/mongodb-odm,alcaeus/mongodb-odm,Xosofox/mongodb-odm,coudenysj/mongodb-odm,lyft/mongodb-odm,doctrine/mongodb-odm,malarzm/mongodb-odm,notrix/mongodb-odm,malarzm/mongodb-odm,jmikola/mongodb-odm,alcaeus/mongodb-odm